BACKGROUND
Field of the Invention
[0002] This invention generally relates to a position sensing device. More specifically,
the present invention relates to a position sensing device that scans a sensing area
with test light and senses the position of a sensing object by detecting reflected
light and/or scattered light from the sensing object within the sensing area. Also,
the present invention relates to a spatial input device that senses input to a spatial
image formed within a space, and a processor. Background Information
[0003] Generally, a position sensing device has been proposed in which a specific area is
scanned and the movement of a hand, finger, or the like within this specific area
is sensed (see, for example,
JP 2013-80516 A and
JP 2014-154063 A).
[0004] With
JP 2013-80516 A, light source units that emit illumination light that is scanned over a coordinate
input plane are provided at two locations, recursive reflection is received from a
recursive reflective member attached to a coordinate support (such as a finger or
an electronic stylus) inserted into the coordinate input plane, and the position (coordinates)
of the coordinate support is sensed from the timing at which the reflected light is
received.
[0005] With
JP 2014-154063 A, a specific scan area is scanned with a detection wave (such as infrared light with
a wavelength of 780 nm), an input device is attached to the user's finger, and the
infrared light is detected with a light receiving element provided to the input device,
thereby detecting that the input device is within the operation area, and a piezoelectric
element is vibrated to notify the user that the input device is within the scan area.
SUMMARY
[0006] With the configuration discussed in
JP 2013-80516 A, however, two-dimensional coordinates within the coordinate input plane are sensed,
but positions (coordinates) cannot be sensed in three-dimensional space.
[0007] Also, with the configuration discussed in
JP 2014-154063 A, whether or not an input device is within an assumed scan region in three-dimensional
space can be confirmed, but a three-dimensional position (coordinates) at a given
point within a specific area cannot be sensed. Also, since the position of an input
device in the scan region is sensed, this input device is required.
[0008] In view of this, it is an object to provide a position sensing device with which
members can be laid out with greater freedom, and the position of a sensing object
in a sensing area can be sensed accurately.
[0009] It is another object to provide a spatial input device with which input from the
user's finger to a spatial image can be reliably detected with a simple configuration.
[0010] In view of the state of the known technology and in accordance with a first aspect
of the present invention, a position sensing device is provided that comprises at
least one light receiver, and a processor. The light receiver is configured to receive
lights that are emitted from a plurality of light exit positions of a scanning light
source component to scan a predetermined area and are reflected by a sensing object
within the predetermined area. The processor is configured to control the scanning
light source component. The processor is configured to sense position of the sensing
object based on a light reception signal of the light receiver. The processor is further
configured to determine from which of the lights the light reception signal is obtained.
The processor is further configured to sense the position of the sensing object based
on optical paths of the lights.
With this configuration, the position of the sensing object can be calculated by scanning
the sensing area with the test light emitted form a plurality of light exit positions,
and detecting the light reflected or scattered by the sensing object located within
the sensing area, so there is more latitude in the position where the light receiver
is attached. Accordingly, there are fewer restrictions on the shape and installation
location of the position sensing device, and the device can be made more compact.
[0011] In accordance with another preferred embodiment according to the position sensing
device mentioned above, the scanning light source component includes at least one
light source that is configured to emit light, and at least one scanning light generator
that is configured to move optical path of the light from the light source in a first
direction and in a second direction that intersects the first direction, and the processor
is configured to control the light source and the scanning light generator.
[0012] With this configuration, it is easy to drive the light source and the scanning light
generator in synchronization. Consequently, the position of the sensing object can
be accurately sensed.
[0013] In accordance with another preferred embodiment according to any one of the position
sensing devices mentioned above, the scanning light source component includes a reflector
that is disposed at at least one of the light exit positions, and that is configured
to reflect the light from the scanning light generator toward the predetermined area.
[0014] With this configuration, since the optical path of the scanning light (i.e. a test
light from the scanning light generator) can be changed by the reflector, there is
greater latitude in the layout of the members of the position sensing device. Examples
of the members include a light source and a test light generator, but are not limited
to these.
[0015] In accordance with another preferred embodiment according to any one of the position
sensing devices mentioned above, the scanning light source component includes the
same number of light sources and scanning light generators as the light exit positions.
Providing the same numbers of light sources and scanning light generators allows the
scanning light (i.e. the test light), to accurately illuminate the sensing area, and
allows the sensing area to be scanned with the test light without any gaps.
[0016] In accordance with another preferred embodiment according to any one of the position
sensing devices mentioned above, the scanning light source component includes the
same number of light sources as the light exit positions, with the number of the light
sources being larger than the number of the at least one scanning light generator,
and lights from the light sources are incident at different angles on the at least
one scanning light generator, and are led toward the corresponding light exit positions,
respectively.
[0017] In accordance with another preferred embodiment according to any one of the position
sensing devices mentioned above, the scanning light source component further includes
an optical path switching component that is configured to alternately guide the optical
path of the light to the light exit positions.
[0018] With this configuration, the number of light sources and scanning light generators
can be reduced, and manufacturing costs will be lower. Also, there will be greater
freedom in the layout of the light sources and scanning light generators, depending
on the layout of the member that converts the optical path of the scanning light (the
test light).
[0019] In accordance with another preferred embodiment according to the position sensing
devices mentioned above, the scanning light source component further includes a polarization
switching component that is disposed between the light source and the scanning light
generator and is configured to switch a polarization direction of the light, and the
optical path switching component includes a polarized beam splitter that is disposed
between the scanning light generator and the light exit positions and is configured
to selectively guide the optical path of the light to the light exit positions by
reflecting or transmitting the light according to the polarization direction of the
light.
[0020] In accordance with another preferred embodiment according to any one of the position
sensing devices mentioned above, the optical path switching component includes a reflection
member that has a reflective face that is configured to selectively reflect the light
to a plurality of reflectors according to incidence position of the light on the reflective
face in the first direction.
[0021] In accordance with another preferred embodiment according to any one of the position
sensing devices mentioned above, the reflective face is split in the first direction.
[0022] In accordance with another preferred embodiment according to any one of the position
sensing devices mentioned above, the processor is configured to control the light
source to stop emitting the light while switching the light exit positions.
[0023] In accordance with another preferred embodiment according to any one of the position
sensing devices mentioned above, while the light is being emitted from one of the
light exit positions, the processor is configured to stop emission of the light from
the other one of the light exit positions, and is configured to acquire time information
about when the light receiver has received the reflection of the light.
[0024] With this configuration, since the emission of scanning light (i.e. the test light)
is performed exclusively in time series, the light exit position where the sensing
light is emitted can be identified even though there are few light receivers. Consequently,
the configuration can be simplified, and a sensing object within the sensing area
can be accurately sensed.
[0025] In accordance with another preferred embodiment according to any one of the position
sensing devices mentioned above, after scanning the predetermined area entirely with
the light from one of the light exit positions, the processor is configured to start
scanning the predetermined area with the light from the other one of the light exit
positions.
[0026] With this configuration, it is easier to synchronize the scanning, and control can
be simplified.
[0027] In accordance with another preferred embodiment according to any one of the position
sensing devices mentioned above, return periods of the lights from the light exit
positions are offset with respect to each other, emissions of the lights from the
light exit positions are alternated every time one line is scanned, and while the
light from one of the light exit positions is in the return period, the predetermined
area is reciprocally scanned with the light from the other one of the light exit positions.
[0028] With this configuration, there is no need for the two scanning light generators to
be operated in synchronization, and a sensing object can be sensed simply and accurately.
Also, since the control is so simple, the controller can be simplified, which reduces
manufacturing costs. Furthermore, scanning light generators of different drive frequencies
can be used. This allows scanning light generators with lower drive frequency accuracy
to be used.
[0029] In accordance with another preferred embodiment according to any one of the position
sensing devices mentioned above, the at least one light receiver has the same number
of light receivers as the light exit positions, the lights from the light exit positons
have different wavelengths with respect to each other, and the light receivers have
band properties to receive the lights from the corresponding light exit positions,
respectively.
With this configuration, from which light exit position the scanning light (i.e. the
test light) is emitted can be determined even when test light is emitted from two
or more places at the same time. Consequently, there is less deviation in time when
scanning with test light from multiple light exit positions, and the sensing object
can be sensed more accurately. Also, since a plurality of beams of test light are
emitted at the same time, there is no need to synchronize multiple light sources and
multiple test light generators, so the scanning light source controller can be simplified.
This allows manufacturing costs to be reduced without lowering the accuracy with which
a sensing object is sensed.
[0030] In accordance with another preferred embodiment according to any one of the position
sensing devices mentioned above, the reflective face has a shape such that scanning
rate of the lights in the predetermined area is a constant.
[0031] In view of the state of the known technology and in accordance with a preferred embodiment,
a spatial input device is provided that comprises any one of the position sensing
devices mentioned above, and an image formation component configured to form an image
in the predetermined area.
[0032] In view of the state of the known technology and in accordance with a second aspect
of the present invention, a position sensing method is provided that comprises receiving
lights that are emitted from a plurality of light exit positions of a scanning light
source component to scan a predetermined area and are reflected by a sensing object
within the predetermined area, controlling the scanning light source component, and
sensing position of the sensing object based on a light reception signal in response
to the receiving of the lights. The sensing of the position further includes determining
from which of the lights the light reception signal is obtained, and sensing the position
of the sensing object based on optical paths of the lights.
[0033] In accordance with another preferred embodiment according to the position sensing
method mentioned above, the controlling of the scanning light source component includes
controlling at least one light source that emits light, and at least one scanning
light generator that moves optical path of the light from the light source in a first
direction and in a second direction that intersects the first direction.
[0034] In accordance with another preferred embodiment according to any one of the position
sensing methods mentioned above, the controlling of the scanning light source component
includes stopping emission of the light from one of the light exit positions while
the light is being emitted from the other one of the light exit positions. The sensing
of the position includes acquiring time information about when the reflection of the
light has been received.
[0035] In accordance with another preferred embodiment according to any one of the position
sensing methods mentioned above, return periods of the lights from the light exit
positions are offset with respect to each other. Emissions of the lights from the
light exit positions are alternated every time one line is scanned. While the light
from one of the light exit positions is in the return period, the predetermined area
is reciprocally scanned with the light from the other one of the light exit positions.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] Referring now to the attached drawings which form a part of this original disclosure:
FIG. 1 is a simplified diagram of the spatial input device in accordance with a first
embodiment;
FIG. 2 is a simplified configuration diagram of the position sensing device;
FIG. 3 is a block diagram of the electrical connections of the position sensing device
shown in FIG. 2;
FIG. 4 is a simplified plan view of an MEMS equipped with a piezoelectric actuator;
FIG. 5A is a diagram of the operation of a first test light generator of the position
sensing device;
FIG. 5B is a diagram of the operation of a second test light generator of the position
sensing device;
FIG. 6 is a timing chart of the operation of the scanning light source component;
FIG. 7A is a first part of a flowchart of the operation of the position sensing device;
FIG. 7B is a second part of the flowchart of the operation of the position sensing
device;
FIG. 7C is a third part of the flowchart of the operation of the position sensing
device;
FIG. 8A is a diagram of the position where test light emitted from a first light exit
position that has been reflected or scattered by a sensing object is received;
FIG. 8B is a diagram of the position where test light emitted from a second light
exit position that has been reflected or scattered by a sensing object is received;
FIG. 9A illustrates tables in which coordinates are associated with the optical path
of test light;
FIG. 9B is a diagram showing that three-dimensional coordinates are computed from
information about the optical path;
FIG. 10 is a diagram of the coordinates when a sensing object is moving in accordance
with a second embodiment;
FIG. 11 is a timing chart of the operation in another example of the position sensing
device in accordance with a third embodiment;
FIG. 12 is a simplified configuration diagram of an example of the position sensing
device in accordance with a fourth embodiment;
FIG. 13 is a simplified configuration diagram of an example of the position sensing
device in accordance with a fifth embodiment;
FIG. 14A is a diagram of two-dimensional scanning of test light from the first light
exit position;
FIG. 14B is a diagram of two-dimensional scanning of test light from the second light
exit position;
FIG. 15 is a simplified layout diagram of another example of the position sensing
device in accordance with a sixth embodiment;
FIG. 16 is a timing chart of the operation of the position sensing device shown in
FIG. 15;
FIG. 17 is a simplified layout diagram of yet another example of the position sensing
device in accordance with a seventh embodiment;
FIG. 18 is a timing chart of the operation of the position sensing device shown in
FIG. 17;
FIG. 19 is a simplified layout diagram of yet another example of the position sensing
device in accordance with an eighth embodiment;
FIG. 20 is a timing chart of the operation of the position sensing device shown in
FIG. 19;
FIG. 21 is a diagram of how the reflective face of the test light generator pivots,
and how test light illuminates an optical path changing mirror;
FIG. 22 is a plan view of the optical path of the position sensing device;
FIG. 23 is a simplified diagram of a state in which a test area is scanned with test
light;
FIG. 24 is a timing chart of the operation in yet another example of the position
sensing device in accordance with a ninth embodiment;
FIG. 25 is a plan view of the optical path changing mirror used in the position sensing
device in accordance with a tenth embodiment;
FIG. 26 is a simplified layout diagram of yet another example of the position sensing
device in accordance with an eleventh embodiment;
FIG. 27 is a block diagram of how the position sensing device shown in FIG. 26 is
connected;
FIG. 28 is a graph of the transmission wavelength of a filter provided to the light
receiver of the position sensing device shown in FIG. 26;
FIG. 29 is a simplified configuration diagram of the position sensing device in accordance
with a twelfth embodiment; and
FIG. 30 is a block diagram of the electrical connections of the position sensing device
shown in FIG. 29.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0037] Selected embodiments will now be explained with reference to the drawings. It will
be apparent to those skilled in the art from this disclosure that the following descriptions
of the embodiments are provided for illustration only and not for the purpose of limiting
the invention as defined by the appended claims and their equivalents.
FIRST EMBODIMENT
[0038] FIG. 1 is a simplified diagram of the spatial input device in accordance with a first
embodiment. As shown in FIG. 1, the spatial input device Ip detects operation input
produced by an operation object (the user's finger Fg) of a spatial image Iv displayed
in an operation input space la by a spatial imaging plate Pt (e.g., image formation
component). The spatial input device Ip includes the position sensing device A in
accordance with this embodiment, and a control device Cnt. The operation input detected
by the spatial input device Ip is sent to a personal computer, a game device, or another
such host device Ht.
[0039] Upon sensing that the user's finger Fg has been inserted into the operation input
space la, the position sensing device A computes the three-dimensional coordinates
of the user's finger Fg, and transfers this to the control device Cnt (an external
device). The control device Cnt includes an operation identification component Op
that identifies operation by the user's finger Fg from the data for the transferred
three-dimensional coordinates. The operation identification component Op performs,
for example, gesture recognition by using changes in the coordinates and changes in
the position over time, touch recognition by detecting the passage of a reference
plane, or the like, and produces input operation information that is a combination
of data for the three-dimensional coordinates and input events for information about
what kind of operation input is performed. The operation identification component
Op then hands the input operation information over to the host device Ht.
[0040] The operation input of the host device Ht can be performed with a virtual operation
device (the spatial image Iv) displayed in space, by using the spatial input device
Ip. With the spatial input device Ip, the position sensing device A and the control
device Cnt (mainly the operation identification component Op) are described as being
separate, but they may instead be integrated.
[0041] The position sensing device in this embodiment will now be described through reference
to the drawings. FIG. 2 is a simplified configuration diagram of the position sensing
device. FIG. 3 is a block diagram of the electrical connections of the position sensing
device shown in FIG. 2. The position sensing device A shown in FIGS. 2 and 3 includes
a light receiver 300, and a processor 400. In the illustrated embodiment, the position
sensing device A includes a scanning light source component 100.
[0042] The position sensing device A scans a sensing area Sa with test light (e.g., scanning
light) emitted from the scanning light source component 100. When the test light shines
on an object that has entered the sensing area Sa (such as the user's finger Fg),
the light reflected or scattered by the user's finger Fg is received by the light
receiver 300. The light receiver 300 sends the processor 400 light reception information
indicating that reflected or scattered light has been received, and the processor
400 acquires position information (coordinate information with respect to a certain
reference, such as the light receiver 300) based on the light reception information.
The various components will now be described in detail.
[0043] The scanning light source component 100 emits test light that is two-dimensionally
scanned over the sensing area Sa. The scanning light source component 100 includes
two light exit positions from which the test lights (e.g., scanning lights) exit.
The light exit positions here will be described as a first light exit position 101
on the left and a second light exit position 102 on the right in the scanning light
source component 100 shown in FIG. 1.
[0044] The scanning light source component 100 has a first optical system 10 that emits
test light from the first light exit position 101 toward the sensing area Sa, and
a second optical system 20 that emits test light from the second light exit position
102 toward the sensing area Sa.
[0045] The first optical system 10 includes a first light source component 11 and a first
test light generator 12 (e.g., scanning light generator). The first light source component
11 includes a light source that emits infrared light (laser light) with a wavelength
in the infrared band. Since infrared light is of a wavelength that cannot be seen
by the user, the position of the user's finger Fg can be sensed without being noticed
by the user. As shown in FIGS. 2 and 3, the first light source component 11 includes
a laser light emitting element (LD; laser diode) 111, a driver 112, a first lens 13,
a first beam splitter 14, and a first monitor-use light receiver 15.
[0046] The first light source component 11 here is equipped with the laser light emitting
element 111, but is not limited to this, and any configuration with which infrared
light of the specified wavelength can be emitted at a specific output or higher can
be employed.
[0047] The emission of the first light source component 11 is controlled by a light source
controller 411 (discussed below) of a scanning light source controller 41. The laser
light emitting element 111 is driven by a signal (power) from the driver 112, and
the driver 112 generates a drive signal for driving the laser light emitting element
111, based on a control signal (emission signal) from the light source controller
411. The intensity, timing, and so forth at which the infrared light is emitted from
the laser light emitting element 111 can be adjusted in this way.
[0048] The laser light emitting element 111 is a point light source, and the emitted infrared
light is scattered light. Accordingly, with the first light source component 11, infrared
light emitted from the laser light emitting element 111 is transmitted by the first
lens 13 and converted into parallel or substantially parallel light. The first lens
13 is a collimator lens.
[0049] The infrared light emitted from the first lens 13 is incident on the first beam splitter
14. The first beam splitter 14 reflects part of the incident infrared light, and transmits
the rest. The light reflected by the first beam splitter 14 is incident on the first
monitor-use light receiver 15. The first monitor-use light receiver 15 sends a monitor
signal based on the incident light to the light source controller 411 of the scanning
light source controller 41.
[0050] The light transmitted by the first beam splitter 14 is incident on the first test
light generator 12. The first test light generator 12 reflects the incident light,
moves the optical axis of the reflected light in a first direction (the horizontal
direction H in FIG. 2) and in a second direction that is perpendicular to the first
direction (the vertical direction V in FIG. 2), and thereby produces test light. The
optical axis of the test light moves in the first and second directions, and the sensing
area Sa is scanned two-dimensionally by the test light. The scanning of the sensing
area Sa with the test light will be discussed below.
[0051] The first test light generator 12 generates test light by shaking a reflective face
120 that reflects incident light, in the first and second directions. The first test
light generator 12 includes an element (MEMS: micro-electromechanical system) 121
that pivots the reflective face 120, a driver 122, and a signal processor 123. The
MEMS will now be described through reference to the drawings. FIG. 4 is a simplified
plan view of an MEMS equipped with a piezoelectric actuator.
[0052] As shown in FIG. 4, the element 121 pivots a mirror 1200 equipped with the reflective
face 120 in the first direction (H direction) and the second direction (V direction)
and thereby deflects the optical axis of the reflected light. The MEMS 121 includes
the mirror 1200, a first elastic deformation part 1211, pivot supports 1212, a second
elastic deformation part 1213, a frame 1214, first actuators 1215, and second actuators
1216. In FIG. 4, the lateral direction is the first direction (H direction) and the
vertical direction is the second direction (V direction).
[0053] The mirror 1200 is a disk-shaped member in which the reflective face 120 is formed
on one of the main faces (here, the face on the side toward the viewer of the drawing).
The first elastic deformation part 1211 is linked to the mirror 1200 at both distal
end portions in the second direction. That is, the mirror 1200 is linked to the center
portion in the second direction of the first elastic deformation part 1211. The pivot
supports 1212 are configured to be able to twist elastically, and the mirror 1200
and the pivot supports 1212 are able to pivot around a first axis C1 extending in
the second direction. In plan view, a second axis C2, which is perpendicular to the
first axis C1, lies along the center of gravity of the mirror 1200. The mirror 1200
and the first elastic deformation part 1211 are configured to be in line symmetry
with the first axis C1 and the second axis C2.
[0054] The pivot supports 1212 are flat members that extend in the second direction, and
are provided as a pair flanking the mirror 1200, and in symmetry with the first axis
C1 and the second axis C2. Both ends of the pivot supports 1212 in the second direction
and both ends of the first elastic deformation part 1211 in the second direction are
linked by the first actuators 1215. Four of the first actuators 1215 are provided
so as to be in symmetry with the first axis C1 and the second axis C2.
[0055] The first actuators 1215 are provided with piezoelectric members, and deform when
power is supplied to them. The four first actuators 1215 are driven as needed to impart
a force to the first elastic deformation part 1211 in the direction in which it twists
around the first axis C1. This force is transferred to the mirror 1200, and causes
the mirror 1200 to rotate around the first axis C1. When the mirror 1200 rotates,
the first elastic deformation part 1211 linked to the mirror 1200 is twisted elastically.
This force from the first actuators 1215 and the elastic force of the first elastic
deformation part 1211 cause the mirror 1200 to pivot around the first axis C1.
[0056] The second elastic deformation part 1213, which extends outward in the first direction,
is linked to the center portion in the second direction of the pivot supports 1212.
The frame 1214 has a rectangular opening window in its center, and the distal end
portions of the second elastic deformation part 1213 are linked to the inner faces
of the opening window of the frame 1214. The second actuators 1216, which extend in
the second direction, are linked to the middle portion of the second elastic deformation
part. The second actuators 1216 extend to opposite sides in the second direction,
flanking the second elastic deformation part 1213. The second actuators 1216 are linked
to the second elastic deformation part 1213 and the frame 1214. Four of the second
actuators 1216 are provided so as to be in symmetry with the first axis C1 and the
second axis C2.
[0057] The second actuators 1216 make use of the same piezoelectric members as the first
actuators 1215, and deform when power is supplied. The four second actuators 1216
are driven as needed to impart a force to the second elastic deformation part 1213
in the direction in which it twists around the second axis C2. This force is transferred
to the pivot supports 1212, and causes the pivot supports 1212 to rotate around the
second axis C2. When rotating around the second axis C2, the mirror 1200, the first
elastic deformation part 1211, the pivot supports 1212, and the first actuators 1215
rotate integrally.
[0058] The second elastic deformation part 1213 twists elastically when the mirror 1200,
the first elastic deformation part 1211, the pivot supports 1212, and the first actuators
1215 rotate. This force from the second actuators 1216 and the elastic force of the
second elastic deformation part 1213 cause the mirror 1200 to pivot around the second
axis C2.
[0059] The MEMS 121 is configured as above, and can pivot the reflective face 120 of the
mirror 1200 in the first and second directions. Here, an example of the MEMS 121 is
described in which piezoelectric actuators are used, but a different configuration
may be used instead, such as electrostatic or magnetic actuators. Also, the MEMS 121
here operates at a frequency of 24 kHz around the first axis C1 and 60 Hz around the
second axis C2, but is not limited to this.
[0060] Nor is the element that drives the reflective face 120 limited to being an MEMS,
and may have a configuration that allows the optical axis of the reflected light to
be moved around two intersecting axes, such as a combination of galvanometer mirrors
or polygon mirrors. The first direction and second direction are perpendicular, but
need not be so, and only need to be intersecting. However, they are preferably perpendicular
or substantially perpendicular in order for the sensing area Sa to be accurately scanned
two-dimensionally with the test light.
[0061] The drive of the MEMS 121 of the first test light generator 12 is controlled by a
scanning controller 412 (discussed below) of the scanning light source controller
41, and a control signal (scan signal) from the scanning controller 412 is inputted
to the driver 122. The driver 122 generates a drive signal that drives the actuators
of the MEMS 121 based on the control signal from the scanning controller 412, and
thereby drives the actuators. The drive signal of the driver 122 causes the MEMS 121
to pivot at a specific frequency and twisting angle in the first direction H and the
second direction V. Also, the signal processor 123 generates a displacement signal
that includes information about the displacement (angle) of the reflective face 120
based on a sensor signal outputted from the MEMS 121, and sends this displacement
signal to the scanning controller 412 of the scanning light source controller 41.
[0062] The second optical system 20 has the same configuration as the first optical system
10. That is, the second optical system 20 includes a second light source component
21 and a second test light generator 22 (e.g., scanning light generator). The second
light source component 21 includes a laser light emitting element 211, a driver 212,
a second lens 23, a second beam splitter 24, and a second monitor-use light receiver
25. Because the components of the second optical system 20 have the same configuration
as those of the first optical system 10, portions that are substantially the same
will not be described again. The first light source component 11 and the second light
source component 21 may be configured to emit infrared light of the same wavelength,
or to emit infrared light of different wavelengths.
[0063] The first optical system 10 and the second optical system 20 emit test light from
the first light exit position 101 and the second light exit position 102, respectively.
With the position sensing device A, reflected or scattered light produced when test
light illuminates a sensing object (such as the user's finger Fg) located within the
sensing area Sa is received by the light receiver 300. The light receiver 300 will
now be described.
[0064] The light receiver 300 outputs a light reception signal upon receiving reflected
infrared light in the infrared band, which is test light emitted from the first light
exit position 101 and/or the second light exit position 102. The light receiver 300
includes a light receiving element 31, a filter 32, and a lens 33. The light receiver
300 is disposed so as to be opposite the side where test light from the first light
exit position 101 and the second light exit position 102 is incident in the sensing
area Sa. However, this is not the only option, and a wide range of positions can be
employed at which reflected and/or scattered light produced when the test light emitted
from the first light exit position 101 and the second light exit position 102 is reflected
by a sensing object can be sensed. Disposing it in the area between the first light
exit position 101 and the second light exit position 102 allows the light receiver
300 to be more compact, and also makes it easier for the scanning light source component
100 and the light receiver 300 to be contained in the same housing, so the position
sensing device A can be more compact.
[0065] The light receiving element 31 is an opto-electric element that receives light of
a specific wavelength band (here, a wavelength band including the infrared light emitted
from the scanning light source component 100), and then emits a light reception signal
(an electrical signal). The higher is the intensity of the light received by the light
receiving element 31, the stronger is the signal that is emitted. With the light receiver
300, the layout is such that sensing light reflected or scattered by the user's finger
Fg passes through the lens 33. When this sensing light is transmitted by the lens
33, it is converged so that it more accurately illuminates the light receiving element
31. This means that high-intensity light is incident on the light receiving element
31, and a strong light reception signal can be outputted.
[0066] The light receiver 300 includes the filter 32 on the opposite side of the lens 33
from the light receiving element 31. The filter 32 is a band pass filter that blocks
light of wavelengths other than the wavelength band in which the sensing light is
included. Using the filter 32 makes it less likely that ambient light will be incident
on the light receiving element 31, so the light reception signal includes less noise
produced by ambient light. Consequently, the light receiving element 31 can output
an accurate and high-strength light reception signal.
[0067] The light receiver 300 in this embodiment has the lens 33 disposed between the filter
32 and the light receiving element 31, but this is not the only option, and the configuration
may instead be such that the filter 32 is between the lens 33 and the light receiving
element 31. A wide range of configurations can be employed, so long as unnecessary
light, that is, light of wavelengths other than the wavelength band in which the sensing
light is included, can be removed from the light that is incident on the light receiving
element 31.
[0068] The processor 400 will now be described. The processor 400 controls the various parts
of the scanning light source component 100, and also computes the position of the
user's finger Fg within the sensing area Sa based on the light reception signal from
the light receiver 300.
[0069] The processor 400 includes a CPU, an MPU, or another such arithmetic processing circuit,
and as shown in FIG. 3, includes the scanning light source controller 41 (e.g., controlling
unit), an arithmetic processor 42 (e.g., calculation unit), a memory 43, a synchronization
signal generator 44, and an external output component 45.
[0070] The processor 400 preferably includes a microcomputer with a control program that
controls the scanning light source component 100. The processor 400 can also include
other conventional components such as an input interface circuit, an output interface
circuit, and storage devices such as a ROM (Read Only Memory) device and a RAM (Random
Access Memory) device. The microcomputer of the processor 400 is programmed to control
the scanning light source component 100. The memory circuit stores processing results
and control programs. The processor 400 is operatively coupled to various parts of
the position sensing device A or the spatial input device Ip in a conventional manner.
The internal RAM of the processor 400 can store statuses of operational flags and
various control data. The internal ROM of the processor 400 can store the programs
for various operations. The processor 400 is capable of selectively controlling any
of the components of the position sensing device A or the spatial input device Ip
in accordance with the control program. It will be apparent to those skilled in the
art from this disclosure that the precise structure and algorithms for the processor
400 can be any combination of hardware and software that will carry out the functions
of the present invention.
[0071] The scanning light source controller 41 is a controller that controls the output
of light from the scanning light source component 100, the speed and range of movement
of the test light, and so forth. The scanning light source controller 41 includes
the light source controller 411 and the scanning controller 412.
[0072] The light source controller 411 is a control circuit that controls the drive of the
first light source component 11 of the first optical system 10 and the second light
source component 21 of the second optical system 20. The light source controller 411
receives a monitor signal from the first monitor-use light receiver 15 of the first
optical system 10. The light source controller 411 generates a control signal that
controls the output of the laser light emitting element 111 of the first light source
component 11, the light exit timing, the light exit duration, and so forth based on
the monitor signal, and sends this to the driver 112. The light source controller
411 also receives a monitor signal from the second monitor-use light receiver 25 of
the second optical system 20. The light source controller 411 generates a control
signal that controls the output of the laser light emitting element 211 of the second
light source component 21, the light exit timing, the light exit duration, and so
forth based on the monitor signal, and sends this to the driver 212.
[0073] Also, the light source controller 411 controls the first light source component 11
and the second light source component 21 so that the exit of infrared light from the
laser light emitting element 111 of the first light source component 11 will not happen
at the same time as the exit of infrared light from the laser light emitting element
211 of the second light source component 21. The timing of the drive will be discussed
in detail below.
[0074] The scanning controller 412 is a control circuit that controls the drive of the first
test light generator 12 of the first optical system 10 and the second test light generator
22 of the second optical system 20. The scanning controller 412 receives a displacement
signal from the signal processor 123 of the first test light generator 12. It then
generates a control signal for suitably pivoting the reflective face 120 based on
this displacement signal, and sends this to the driver 122. The scanning controller
412 receives a displacement signal from a signal processor 223 of the second test
light generator 22. It then generates a control signal for suitably pivoting the reflective
face 220 based on this displacement signal, and sends this to a driver 222.
[0075] The light source controller 411 and the scanning controller 412 synchronously drive
the first light source component 11, the first test light generator 12, the second
light source component 21, and the second test light generator 22, thereby scanning
the sensing area Sa two-dimensionally with test light. The scanning light source controller
41 is able to access the memory 43. The scanning light source controller 41 drives
the first optical system 10 and the second optical system 20 based on optical scanning
pattern information stored in the memory 43.
[0076] The memory 43 includes a storage unit such as a ROM (read-only), a RAM (writable),
or a flash memory. The memory 43 is equipped with a control table in which information
about the light exit timing of the first light source component 11, the pivot angle
of the reflective face 120 of the first test light generator 12, the light exit timing
of the second light source component 21, and the pivot angle of the reflective face
220 of the second test light generator 22 are listed in time series. This control
table may also handle other data as well. Whether light exits the first light source
component 11, the pivot angle of the reflective face 120 (the MEMS 121), whether light
exits the second light source component 21, and the pivot angle of the reflective
face 220 (the MEMS 221), all at a certain time, are optical scanning pattern information.
[0077] The arithmetic processor 42 includes a receiver 421 and an arithmetic unit 422. The
receiver 421 is a circuit that receives a light reception signal from the light receiving
element 31 of the light receiver 300. The receiver 421 also receives a synchronization
signal from the synchronization signal generator 44. The receiver 421 associates the
synchronization signal and the light reception signal from the light receiving element
31, and sends them to the arithmetic unit 422.
[0078] The arithmetic unit 422 is a circuit that computes position data (coordinate data)
for the user's finger Fg within the sensing area Sa from the light reception signal
and the synchronization signal. The arithmetic unit 422 accesses the memory 43 and
designates the optical path of test light reflected or scattered by the user's finger
Fg from the control table and the light reception signal and synchronization signal.
The three-dimensional coordinates of the user's finger Fg are then calculated from
the designated optical path of the test light. The method for calculating the three-dimensional
coordinates will be discussed below.
[0079] The synchronization signal generator 44 includes a signal generation circuit for
generating a synchronization signal. Because operation is based on a synchronization
signal, the light source controller 411 and the scanning controller 412 are driven
in synchronization. The synchronization signal is also sent to the arithmetic processor
42, and the duration of the exit of test light from the scanning light source component
100 and the duration of the reception of test light by the light receiver 300 can
be acquired from the synchronization signal associated with the light reception signal.
[0080] The external output component 45 is connected to an external device, and includes
a communication circuit for sending position information (three-dimensional coordinates)
for the user's finger Fg to the external device. The external output component 45
may be configured to perform data communication over a wire, or to perform data communication
wirelessly.
[0081] The operation of the position sensing device A will now be described through reference
to the drawings. FIG. 5A is a diagram of the operation of a first test light generator
of the position sensing device, and FIG. 5B is a diagram of the operation of a second
test light generator of the position sensing device.
[0082] FIG. 5A shows the operation of the MEMS 121 of the first test light generator 12.
The rectangle in FIG. 5A indicates the sensing area Sa. The sensing area Sa is scanned
two-dimensionally with a spot Spt of test light. FIG. 5A shows the pivot of the reflective
face 120 of the first test light generator 12 around the first axis C1, that is, the
pivot Os1 in the first direction, and the pivot around the second axis C2, that is,
the pivot Os2 in the second direction. The first and second directions in FIG. 5A
correspond to the first direction (horizontal direction) and second direction (vertical
direction) in FIG. 2.
[0083] In FIG. 5A, the pivot Os1 in the first direction is plotted with the pivot angle
(normal line position) of the reflective face 120 on the horizontal axis and time
on the vertical axis, and the pivot Os2 in the second direction is plotted with time
on the horizontal axis and the pivot angle (normal line position) of the reflective
face 220 on the vertical axis. With the position sensing device A, the first light
source component 11, the first test light generator 12, the second light source component
21, and the second test light generator 22 are driven based on the control signals
generated by the light source controller 411 and the scanning controller 412. The
reflective face 120 pivots in the first direction at a constant frequency, and also
pivots in the second direction at a constant frequency.
[0084] With the position sensing device A, two-dimensional scanning of the sensing area
Sa is performed by shifting the movement of the spot Spt to one side in the first
direction to the second direction, and repeating. When such scanning is performed,
the scanning light source controller 41 performs control as follows. As shown in FIG.
5A, the scanning light source controller 41 causes the laser light emitting element
111 to emit infrared light when the angle of the reflective face 120 moves to one
side in the first direction (here, from left to right). When the angle of the reflective
face 120 moves to the other side in the first direction (right to left), the emission
of infrared light from the laser light emitting element 111 is stopped. This period
in which the emission of infrared light from the laser light emitting element 111
is stopped is the first direction return period (horizontal return period). In FIG.
5A, the return period of the pivot Os1 in the first direction is indicated by a broken
line. In this embodiment, the laser light emitting element 111 emits light only when
the spot Spt scans to one side in the first direction, but this is not the only option.
The laser light emitting element 111 may emit light so that the spot Spt goes back
and forth in the first direction.
[0085] The reflective face 120 also pivots in the second direction, at a lower frequency
than the frequency of the pivot in the first direction. With the position sensing
device A, the scanning light source controller 41 controls the emission of infrared
light from the laser light emitting element 111 during movement to one side in the
first direction (left to right) while the angle of the reflective face 120 moves to
one side in the second direction (here, top to bottom). Therefore, the spot Spt of
test light that actually illuminates the sensing area Sa moves in both the first and
second directions, that is, it moves at an angle.
[0086] The scanning light source controller 41 adjusts the frequency of the first and second
directions so that the angle of the reflective face 120 will move by a width that
is equal to or slightly less than the diameter of the spot Spt of test light in the
second direction during one round trip in the first direction (equal to one line).
Consequently, movement of the spot Spt of test light to one side in the first direction
is repeated while being shifted one line at a time in the second direction, and the
sensing area Sa is evenly scanned with the spot Spt of test light. Movement of the
spot Spt is called scanning, and movement in the first direction will sometimes be
called first direction scanning, and movement in the second direction called second
direction scanning.
[0087] When the angle of the reflective face 120 moves to the other side in the second direction
(bottom to top), the emission of infrared light from the laser light emitting element
111 is stopped. This period in which the angle of the reflective face 120 moves to
the other side in the second direction is the second direction return period (vertical
return period). In FIG. 5A, the return period of the pivot Os1 in the first direction
is indicated by a broken line.
[0088] The scanning light source controller 41 controls the first optical system 10 of the
scanning light source component 100 as discussed above, so that scanning is repeatedly
carried out in which the spot Spt of test light emitted from the first light exit
position 101 moves from the left to the right and from the top to the bottom one line
at a time.
[0089] Also, as shown in FIG. 5B, the second optical system 20 operates the same as the
first optical system 10, and two-dimensional scanning of the sensing area Sa with
the spot Spt of test light is done in the same way with the test light from the second
optical system 20.
[0090] With the position sensing device A, the scanning light source controller 41 controls
the scanning light source component 100 so that test light from the first light exit
position 101 and test light from the second light exit position 102 will not be emitted
in the sensing area Sa at the same time. The control over the scanning light source
component 100 by the scanning light source controller 41 will now be described through
reference to the drawings. FIG. 6 is a timing chart of the operation of the scanning
light source component.
[0091] In FIG. 6, the horizontal axis is time, and the uppermost level shows the pivot angle
of the reflective face 120 of the first test light generator 12 in the first and second
directions. The level below this shows the pivot angle of the reflective face 220
of the second test light generator 22 in the first and second directions. The level
below this shows the emission of infrared light from the laser light emitting element
111 of the first light source component 11. The level below this shows the emission
of infrared light from the laser light emitting element 211 of the second light source
component 21. The lowermost level is the light reception signal from the light receiving
element 31 of the light receiver 300. Also shown is a detail view of the portion received
by the light receiving element 31.
[0092] As shown in FIG. 6, the arithmetic unit 422 pivots the reflective face 120 (the MEMS
121) so that the reflected light (test light) exceeds the illumination range in the
first direction. The light source controller 411 then controls the timing at which
light is emitted from the first light source component 11, so that the test light
illuminates within the illumination range of the sensing area Sa.
[0093] The arithmetic unit 422 then pivots the reflective face 120 so that the reflected
light (test light) exceeds the illumination range in the second direction. The light
source controller 411 then controls the timing at which light is emitted from the
first light source component 11, so that the test light illuminates within the illumination
range of the sensing area Sa. In the first optical system 10, the period in which
the line indicating movement of the reflective face 120 in the first direction is
rising to the right (period Tm2) is the return period (vertical return period), and
infrared light is emitted from the laser light emitting element 111 in the scanning
period, which is the period in which the line is falling to the right (period Tm1).
More precisely, with the first optical system 10, in the period Tm1, when the reflective
face 120 moves to one side in the first direction (left to right), infrared light
is emitted from the laser light emitting element 111 of the first light source component
11.
[0094] The scanning light source controller 41 controls the scanning light source component
100 so that the first test light generator 12 of the first optical system 10 and the
second test light generator 22 of the second optical system 20 will alternately suppress
the return period in the second direction. As shown in FIG. 5, in the period Tm1 the
second test light generator 22 is in the return period (vertical return period), and
in the period Tm2 the first test light generator 12 is in the return period (vertical
return period). With the position sensing device A, in the period Tm1 the sensing
area Sa is scanned two-dimensionally with test light from the first light exit position
101, and in the period Tm2 the sensing area Sa is scanned two-dimensionally with test
light from the second light exit position 102. Consequently, test light from the first
light exit position 101 and test light from the second light exit position 102 will
not illuminate the sensing area Sa at the same time.
[0095] The procedure for sensing a sensing object (the user's finger Fg) with the position
sensing device A will now be described through reference to the drawings. FIG. 7A
is a first part of a flowchart of the operation of the position sensing device. FIG.
7B is a second part of the flowchart of the operation of the position sensing device.
FIG. 7C is a third part of the flowchart of the operation of the position sensing
device. FIG. 8A is a diagram of the position where test light emitted from the first
light exit position that has been reflected or scattered by a sensing object is received.
FIG. 8B is a diagram of the position where test light emitted from a second light
exit position that has been reflected or scattered by a sensing object is received.
FIG. 9A illustrates tables in which coordinates are associated with the optical path
of test light. FIG. 9B is a diagram showing that three-dimensional coordinates are
computed from information about the optical path.
[0096] As shown in FIG. 7A, the scanning light source controller 41 acquires information
about the timing of the drive of the first optical system 10 and the second optical
system 20 from the control tables of the memory 43 (step S101). The scanning controller
412 of the scanning light source controller 41 generates a scanning signal (control
signal) indicating the pivot timing of the MEMS 121 of the first test light generator
12 in the first and second directions based on information about drive timing and
the synchronization signal from the synchronization signal generator 44, and sends
this to the driver 122. The light source controller 411 sends an emission signal (control
signal) to the driver 112 so that the laser light emitting element 111 of the first
light source component 11 will emit light when the MEMS 121 pivots so as to produce
a certain illumination angle for the test light. Thus, test light is emitted from
the first light exit position 101 when a control signal is sent to the first optical
system 10 (step S102).
[0097] The light receiving element 31 of the light receiver 300 sends reception signals
to the processor 400 at regular intervals, and the receiver 421 of the arithmetic
processor 42 acquires a light reception signal from the light receiving element 31
(step S103). The arithmetic processor 42 determines whether or not the user's finger
Fg has been detected (step S104). The arithmetic processor 42 determines that the
user's finger Fg has been detected when the light reception signal that is at or above
a predetermined threshold is acquired. When the arithmetic processor 42 determines
that the user's finger Fg has been detected (Yes in step S104), then the receiver
421 receives a synchronization signal from the synchronization signal generator 44,
associates the light reception signal with the synchronization signal, and sends them
to the arithmetic unit 422. The arithmetic unit 422 stores reception information included
in the light reception signal and the synchronization signal in the memory 43, and
acquires coordinates of the user's finger Fg with respect to the first light exit
position 101 based on the timing of the acquisition of the light reception signal
and the synchronization signal (step S105). When the arithmetic processor 42 determines
that the user's finger Fg has not been detected (No in step S104), the process proceeds
to step S106.
[0098] The scanning light source controller 41 checks whether or not the scanning is finished
(step S106). Whether the scanning has ended is determined by whether or not the reflective
face 120 (MEMS 121) is in the return period, based on a displacement signal from the
signal processor 123 of the first test light generator 12.
[0099] If scanning has not ended (No in step S106), the emission of test light from the
first light exit position 101 is continued (return to step S102). If scanning has
ended (Yes in step S106), then the arithmetic processor 42 checks whether or not the
user's finger Fg has been detected in the sensing area Sa in step S104 (step S107
in FIG. 7B).
[0100] As mentioned above, in step S104, an example of checking whether or not the user's
finger Fg is in the sensing area Sa is to determine whether or not the light receiving
element 31 is at or above a predetermined threshold, but this is not the only option.
[0101] Also, as mentioned above, in step S105, if the user's finger Fg has been detected
in the sensing area Sa (Yes in step S104), then the arithmetic unit 422 calls up light
reception information, acquires detection information (coordinates) for the user's
finger Fg with respect to the first light exit position 101, and stores this information
in the memory 43 (step S105).
[0102] The acquisition by the arithmetic unit 422 of the coordinates of the detection position
with respect to the first light exit position 101 involves acquiring the synchronization
signal associated with the light reception signal. A time t1 since the start of light
exit from the laser light emitting element 111 of the first light source component
11 (see the detail portion of FIG. 6) is acquired based on the synchronization signal
and the control table. The laser light emitting element 111 emits light in synchronization
with the pivoting of the reflective face 120, so a position x1 of the user's finger
Fg in the first direction with respect to the first light exit position 101 can be
confirmed by acquiring the time t1 since the start of emission from the laser light
emitting element 111.
[0103] Similarly, the arithmetic unit 422 acquires a pivot angle L1 in the second direction
of the reflective face 120 (see the detail portion of FIG. 6) based on a displacement
signal from the signal processor 123 of the first test light generator 12. A position
y1 of the user's finger Fg in the second direction with respect to the first light
exit position 101 can be confirmed from this pivot angle L1 in the second direction.
Because of this, the coordinates (x1, y1) of the user's finger Fg within the sensing
area Sa as seen from the first light exit position 101 can be acquired (see FIG. 8A).
[0104] If the user's finger Fg is not detected in the sensing area Sa by the test light
from the first light exit position 101 (No in step S107), the position sensing device
A confirms whether or not detection of the user's finger Fg within the sensing area
Sa has ended (step S117 in FIG. 7C). Examples of the end of detection is when an end
signal is received from an external device, and when it is detected that the user
has operated a control component (such as a switch; not shown in the drawings), but
these are just examples.
[0105] If the processor 400 confirms that the detection of the user's finger Fg within the
sensing area Sa is to be ended (Yes in step S117 in FIG. 7C), then the detection of
the user's finger Fg within the sensing area Sa is ended. If the processor 400 confirms
that the detection in the sensing area Sa is to be continued (No in step S117 in FIG.
7C), then detection of the user's finger Fg within the sensing area Sa is performed
with the test light from the first light exit position 101 (return to step S101 in
FIG. 7A). As discussed above, if the user's finger Fg is not detected with the test
light from the first light exit position 101, emission of the test light from the
first light exit position 101 is repeated. Therefore, the emission of test light from
the second light exit position 102 is stopped, and this reduces power consumption.
Also, because the first light exit position 101 is disposed at a position where the
test light will illuminate the sensing area Sa at an angle at which it does not shine
directly at the user, safety is enhanced in the event of a malfunction, etc.
[0106] If the user's finger Fg is detected by scanning the sensing area Sa with the test
light from the first light exit position 101 (Yes in step S107 in FIG. 7B), the scanning
light source controller 41 causes the second light exit position 102 to emit test
light (step S108). More specifically, the following happens. The scanning controller
412 generates a scanning signal (control signal) indicating the timing at which the
MEMS 221 of the second test light generator 22 pivots in the first direction or the
second direction based on information about the drive timing and the synchronization
signal from the synchronization signal generator 44, and sends this signal to the
driver 222. The light source controller 411 sends a light emission signal (control
signal) to the driver 212 so that the laser light emitting element 211 of the second
light source component 21 will emit light when the MEMS 221 pivots so as to produce
a certain illumination angle for the test light.
[0107] The light receiving element 31 of the light receiver 300 sends reception signals
to the processor 400 at regular intervals, and the receiver 421 of the arithmetic
processor 42 acquires a light reception signal from the light receiving element 31
(step S109). As discussed above, it can be confirmed from the synchronization signal
whether light with which the light reception signal is received is being emitted from
the first light exit position 101 or from the second light exit position 102.
[0108] The arithmetic processor 42 determines whether or not the user's finger Fg has been
detected (step S110). The arithmetic processor 42 determines that the user's finger
Fg has been detected when the light reception signal that is at or above a predetermined
threshold is acquired. When the arithmetic processor 42 determines that the user's
finger Fg has been detected (Yes in step S110), then the receiver 421 receives a synchronization
signal from the synchronization signal generator 44, associates the light reception
signal with the synchronization signal, and sends them to the arithmetic unit 422.
The arithmetic unit 422 stores reception information included in the light reception
signal and the synchronization signal in the memory 43, and acquires coordinates of
the user's finger Fg with respect to the second light exit position 102 based on the
timing of the acquisition of the light reception signal and the synchronization signal
(step S111). When the arithmetic processor 42 determines that the user's finger Fg
has not been detected (No in step S110), the process proceeds to step S112.
[0109] The scanning light source controller 41 then confirms whether or not the scanning
has ended (step S112). The end of the scanning is determined by ascertaining whether
or not the reflective face 220 (MEMS 221) is in its return period based on a displacement
signal from the signal processor 223 of the second test light generator 22.
[0110] If scanning has not ended (No in step S112), the emission of test light from the
second light exit position 102 is continued (return to step S108). If scanning has
ended (Yes in step S112), the arithmetic processor 42 confirms whether or not the
user's finger Fg was detected in the sensing area Sa in step S110 (step S113).
[0111] As mentioned above, in step S110, confirmation of whether or not the user's finger
Fg is in the sensing area Sa is the same as discussed above. An example of confirming
whether or not the user's finger Fg is in the sensing area Sa is to determine whether
or not the light receiving element 31 is at or above a predetermined threshold, but
this is not the only option.
[0112] Also, as mentioned above, in step S111, if the user's finger Fg has been detected
in the sensing area Sa (Yes in step S110), then the arithmetic unit 422 calls up light
reception information, acquires information (coordinates) about the detection position
of the user's finger Fg with respect to the second light exit position 102, and stores
this information in the memory 43 (step S111).
[0113] The acquisition by the arithmetic unit 422 of the coordinates of the detection position
with respect to the second light exit position 102 involves acquiring the synchronization
signal associated with the light reception signal. A time t2 since the start of light
exit from the laser light emitting element 211 of the second light source component
21 (see the detail portion of FIG. 6) is acquired based on the synchronization signal
and the control table. The laser light emitting element 211 emits light in synchronization
with the pivoting of the reflective face 220, so a position x2 of the user's finger
Fg in the first direction with respect to the second light exit position 102 can be
confirmed by acquiring the time t2 since the start of emission from the laser light
emitting element 211.
[0114] Similarly, the arithmetic unit 422 acquires a pivot angle L2 in the second direction
of the reflective face 220 (see the detail portion of FIG. 6) based on a displacement
signal from the signal processor 223 of the second test light generator 22. A position
y2 of the user's finger Fg in the second direction with respect to the second light
exit position 102 can be confirmed from this pivot angle L2 in the second direction.
Because of this, the coordinates (x2, y2) of the user's finger Fg within the sensing
area Sa as seen from the second light exit position 102 can be acquired (see FIG.
8B).
[0115] If the user's finger Fg is not detected in the sensing area Sa by the test light
from the second light exit position 102 (No in step S113), the position sensing device
A confirms whether or not detection of the user's finger Fg within the sensing area
Sa has ended (step S117 in FIG. 7C). The operation from step S117 on is the same,
and therefore will not be described again.
[0116] The arithmetic unit 422 designates the optical path of the test light emitted from
the first light exit position 101 and the second light exit position 102 from the
coordinates of the user's finger Fg as seen from the first light exit position 101
and from the coordinates of the user's finger Fg as seen from the second light exit
position 102, both of which are stored in the memory 43 (step S114 in FIG. 7C). The
following is an example of the method for designating the test light. The arithmetic
unit 422 designates the optical path of the test light based on coordinate information
for the detected user's finger Fg with respect to the first light exit position 101,
and coordinate information with respect to the second light exit position 102.
[0117] With the position sensing device A, since the sensing area Sa is scanned in the first
and second directions with test light from the first light exit position 101 and the
second light exit position 102, the optical path of test light can be designated from
the coordinates for the user's finger Fg with respect to the first light exit position
101 and the second light exit position 102. As shown in FIG. 9A, the arithmetic unit
422 refers to an optical path table that associates the optical path of the test light,
and acquires information about an optical path B11 of test light that illuminates
the user's finger Fg from the first light exit position 101, and about an optical
path B22 of test light that illuminates the user's finger Fg from the second light
exit position 102.
[0118] As shown in FIG. 9B, three-dimensional coordinates of the user's finger Fg are acquired
based on the optical path intersections. If the optical paths do not intersect, approximation
computation is performed, such as using the middle point between nearest points. Also,
the angles of the reflective face 120 and the reflective face 220 may be acquired
from the synchronization signal associated with the light reception signal and the
control table, and the optical path of the test light may be designated from these
angles of the reflective face 120 and the reflective face 220.
[0119] The three-dimensional coordinates of the user's finger Fg within the sensing area
Sa are then computed from the optical path of test light from the first light exit
position 101 and the optical path of test light from the second light exit position
102 (step S115). The arithmetic unit 422 transfers the computed three-dimensional
coordinates of the user's finger Fg to the external output component 45, and the external
output component 45 sends the three-dimensional coordinates of the user's finger Fg
to an external device (step S116). After the three-dimensional coordinates have been
sent, it is confirmed whether or not to continue detection in the sensing area Sa
(step S117). The operation from step S117 on is the same, and therefore will not be
described again.
[0120] As discussed above, with the position sensing device A in this embodiment, the light
receiver 300 senses light that has been reflected and/or scattered by a sensing object,
originating in test light emitted in a sensing area Sa from both the first light exit
position 101 and the second light exit position 102, which are disposed apart from
each other in different positions. The optical path of test light emitted from the
first light exit position 101 and the optical path of test light emitted from the
second light exit position 102 are then designated based on reflected and/or scattered
light sensed by the light receiver 300, and the three-dimensional coordinates of the
sensing object are computed. Because of this configuration, the light receiver 300
need only receive light reflected and/or scattered by the sensing object, originating
in the test light emitted from the first light exit position 101 and the test light
emitted from the second light exit position 102, so there is greater latitude in the
position of the light receiver 300. This makes it possible to improve the sensing
accuracy of the position sensing device A.
[0121] Also, the light receiver 300 need only sense reflected light or scattered light,
so the configuration can be simple.
[0122] Also, the user's finger Fg is used as an example of a sensing object in this embodiment,
but this is not the only option, and anything having a surface that can reflect test
light can be used. The same applies to the sensing objects in the following embodiments.
[0123] In the illustrated embodiment, the position sensing device A includes the light receiver
300 (e.g., at least one light receiver), and the processor 400. In the illustrated
embodiment, the position sensing device A also includes the scanning light source
component 100. The scanning light source component 100 is configured to emit the test
lights (e.g., lights or scanning lights) from the first and second light exit positons
101 and 102 (e.g., a plurality of different light exit positions), respectively, to
scan the sensing area Sa (e.g., predetermined area) with the test lights. The light
receiver 300 is configured to receive the reflected infrared lights or the test lights
that are emitted from the first and second light exit positons 101 and 102 and are
reflected by the user's finger Fg (e.g., sensing object) within the sensing area Sa.
The processor 400 is configured to control the scanning light source component 100,
and is configured to sense or calculate the position of the user's finger Fg based
on the light reception signal of the light receiver 300. The processor 400 is further
configured to determine from which of the test lights the light reception signal is
obtained, and is configured to sense or calculate the position of the user's finger
Fg based on the optical paths of the test lights.
[0124] In the illustrated embodiment, with the position sensing device A as mentioned above,
the scanning light source component 100 includes the first and second light source
components 11 and 21 (e.g., at least one light source) that are configured to emit
the lights (infrared light, laser light, and so forth), and the first and second test
light generators 12 and 22 (e.g., at least one scanning light generator) that are
configured to move the optical paths of the lights from the first and second light
source components 11 and 21 in the first direction (or horizontal direction H) and
in the second direction (or vertical direction V) that intersects the first direction.
The processor 400 is configured to control the first and second light source components
11 and 21 and the first and second test light generators 12 and 22.
[0125] In the illustrated embodiment, with the position sensing device A as mentioned above,
the scanning light source component 100 includes the same number of (two) light sources
(first and second light source components 11 and 21) and (two) scanning light generators
(first and second test light generators 12 and 22) as the first and second light exit
positions 101 and 102, as illustrated in FIG. 2.
[0126] In the illustrated embodiment, with the position sensing device A as mentioned above,
while the test light is being emitted from one of the first and second light exit
positions 101 and 102, the processor 400 is configured to stop emission of the test
light from the other one of the first and second light exit positions 101 and 102,
and is configured to acquire the reception information and the synchronization signal
(e.g., time information) about when the light receiver 300 has received the reflection
of the test light.
[0127] In the illustrated embodiment, with the position sensing device A as mentioned above,
after scanning the sensing area Sa entirely with the test light from one of the first
and second light exit positions 101 and 102, the processor 400 is configured to start
scanning the sensing area Sa with the test light from the other one of the first and
second light exit positions 101 and 102, as illustrated in FIG. 6.
[0128] In the illustrated embodiment, with the position sensing device A as mentioned above,
the processer 400 is configured to sense or calculate the position of the user's finger
Fg based on a table indicative of relationship between coordinate and the optical
paths B11 and B22 of the test lights, as illustrated in FIG. 9A.
[0129] In the illustrated embodiment, with the position sensing device A as mentioned above,
the light receiver 300 is configured to detect the user's finger Fg based on a predetermined
threshold. More specifically, the processor 400 can determine that the user's finger
Fg is detected in the sensing area Sa when the magnitude of the light reception signal
detected by the light receiver 300 is at or above the predetermined threshold.
[0130] In the illustrated embodiment, with the position sensing device A as mentioned above,
the test light from one of the first and second light exit positions 101 and 102 (the
first light exit position 101 in FIG. 7A) is repeatedly emitted (S102) without emitting
the test light from the other one of the first and second light exit positions 101
and 102 (the second light exit position 102 in FIG. 7A) while the light receiver 300
does not receive the test light from the one of the first and second light exit positons
101 and 102 that is reflected by the user's finger Fg within the sensing area Sa (No
in S107 in FIG. 7B), as illustrated in FIGS. 7A, 7B, 7C. More specifically, if it
is determined that the user's finger Fg has not been detected with the test light
from the first light exit position 101 (No in step S107 in FIG. 7B), then the process
repeatedly goes back to step S102 in FIG. 7A, and the emission of the test light from
the first light exit position 101 is repeated while the emission of the test light
from the second light exit position 102 is stopped.
[0131] In the illustrated embodiment, with the position sensing device A as mentioned above,
the processor 400 is configured to sense or calculate the position of the user's finger
Fg as an intersection of the optical paths B11 and B22 of the test light, as illustrated
in FIG. 9B.
[0132] In the illustrated embodiment, the spatial input device Ip includes the position
sensing device A as mentioned above, and the spatial imaging plate Pt (e.g., image
formation component) configured to form an image in the sensing area Sa, as illustrated
in FIG. 1.
[0133] In the illustrated embodiment, the position sensing method includes receiving the
reflected infrared lights or the test lights that are emitted from the first and second
light exit positions 101 and 102 of the scanning light source component 100 to scan
the sensing area Sa and are reflected by the user's finger Fg within the sensing area
Sa, controlling the scanning light source component 100, and sensing the position
of the user's finger Fg based on the light reception signal in response to the receiving
of the reflected infrared lights lights or the test lights. The sensing of the position
further including determining from which of the test lights the light reception signal
is obtained, and sensing the position of the user's finger Fg based on the optical
paths of the test lights.
[0134] In the illustrated embodiment, with the position sensing method as mentioned above,
the controlling of the scanning light source component 100 includes controlling the
first and second light source components 11 and 21 (e.g., at least one light source)
that are configured to emit the lights (infrared light, laser light, and so forth),
and the first and second test light generators 12 and 22 (e.g., at least one scanning
light generator) that are configured to move the optical paths of the lights from
the first and second light source components 11 and 21 in the first direction (or
horizontal direction H) and in the second direction (or vertical direction V) that
intersects the first direction.
[0135] In the illustrated embodiment, with the position sensing method as mentioned above,
the controlling of the scanning light source component 100 includes stopping emission
of the test light from one of the first and second light exit positions 101 and 102
while the test light is being emitted from the other one of the first and second light
exit positions 101 and 102. The sensing of the position includes acquiring the reception
information and the synchronization signal (e.g., time information) about when the
light receiver 300 has received the reflection of the test light.
[0136] In the illustrated embodiment, the processor 400 includes the scanning light source
controller 41 (e.g., controlling unit), and the arithmetic processor 42 (e.g., calculation
unit), as illustrated in FIG. 3. The scanning light source controller 41 is configured
to control emission of the test lights (e.g., scanning lights) from the first and
second light exit positions 101 and 102 (e.g., a plurality of different light exit
positions), respectively, to scan the sensing area Sa with the test lights. The arithmetic
processor 42 is configured to calculate position of the user's finger Fg (e.g., sensing
object) based on the light reception signal obtained in response to the test lights
being reflected by the user's finger Fg. The arithmetic processor 42 is further configured
to determine from which of the test lights the light reception signal is obtained,
and is configured to calculate the position of the user's finger Fg based on the optical
paths of the test lights.
[0137] In the illustrated embodiment, there is provided the position sensing device A with
which members can be laid out with greater freedom, and the position of the user's
finger Fg (e.g., sensing object) in the sensing area Sa can be sensed accurately.
With the position sensing device A, the sensing area Sa is scanned with the test lights
emitted from the plurality of different light exit positions 101 and 102, the sensing
light that is reflected or scattered by the sensing object Fg within the sensing area
Sa is received, the position of the sensing object Fg is calculated, and the processor
400 determines from which light exit position the light reception signal is obtained
by receiving the sensing light based on the test light that is emitted.
SECOND EMBODIMENT
[0138] The user's finger Fg (the sensing object) will sometimes move. This scenario will
now be described through reference to the drawings. FIG. 10 is a diagram of the coordinates
when the sensing object is moving. The horizontal axis in FIG. 10 is the frames, the
upper row is the sensing coordinates for a sensing object with respect to the first
light exit position 101, and the lower row is the sensing coordinates for a sensing
object with respect to the second light exit position 102. The position sensing device
A alternately performs overall scanning of the sensing area Sa with test light from
the first light exit position 101 and overall scanning of the sensing area Sa with
test light from the second light exit position 102. Those components that are substantially
the same as the components described above will be numbered the same and not described
in detail again.
[0139] As shown in FIG. 10, in frames F1, F3, and F5, the arithmetic unit 422 acquires measured
coordinates Pf1, Pf3, and Pf5 for the position of the user's finger Fg with respect
to the first light exit position 101 when two-dimensional scanning is performed with
test light from the first light exit position 101. In frames F2 and F4, the arithmetic
unit 422 acquires measured coordinates Pf2 and Pf4 for the position of the user's
finger Fg with respect to the second light exit position 102 when two-dimensional
scanning is performed with test light from the second light exit position 102.
[0140] Also, the arithmetic unit 422 computes surmised coordinates Pv2 of the frame F2,
which are surmised from the measured coordinates Pf1 of the frame F1 and the measured
coordinates Pf3 of the frame F3. The computation of the surmised coordinates Pv2 is
the middle point between the measured coordinates Pf1 and the measured coordinates
Pf3. Surmised coordinates Pv4, which are surmised from the measured coordinates Pf3
of the frame F3 and the measured coordinates Pf5 of the frame F5, are similarly computed.
Furthermore, the arithmetic unit 422 computes surmised coordinates Pv3 of the frame
F3, which are surmised from the measured coordinates Pf2 of the frame F2 and the measured
coordinates Pf4 of the frame F4.
[0141] The arithmetic unit 422 then computes the three-dimensional coordinates of the user's
finger Fg in each frame from the measured coordinates and the surmised coordinates.
For example, the three-dimensional coordinates of the user's finger Fg in the frame
F2 are acquired from the surmised coordinates Pv2 of the user's finger Fg in the frame
F2 with respect to the first light exit position 101, and the measured coordinates
Pf2 with respect to the second light exit position 102. Thus using measured coordinates
and surmised coordinates makes it possible to accurately acquire three-dimensional
coordinates when the user's finger Fg moves.
THIRD EMBODIMENT
[0142] Another example of the position sensing device in accordance with a third embodiment
will now be described through reference to the drawings. FIG. 11 is a timing chart
of the operation in another example of the position sensing device in accordance with
the third embodiment. The position sensing device A in this embodiment is the same
as the position sensing device A in the first embodiment, except that the control
of the scanning light source controller 41 by the scanning light source component
100 is different. Specifically, the basic configuration is the same as that of the
position sensing device A in the first embodiment, so the same components are numbered
the same and will not be described again in detail.
[0143] As shown in FIG. 11, the rate at which the reflective face 120 (MEMS 121) of the
first test light generator 12 of the first optical system 10 pivots in the second
direction is faster during the period of pivoting from bottom to top (return period)
than during the period of pivoting from top to bottom (scanning period). Similarly,
the rate at which the reflective face 220 (MEMS 221) of the second test light generator
22 of the second optical system 20 pivots in the second direction is faster during
the period of pivoting from bottom to top (return period) than during the period of
pivoting from top to bottom (scanning period).
[0144] The timing at which the reflective face 120 (MEMS 121) of the first test light generator
12 and the reflective face 220 (MEMS 221) of the second test light generator 22 are
switched to pivot in the second direction is offset. For example, the scanning light
source controller 41 drives the first optical system 10 and the second optical system
20 so that the reflective face 220 (MEMS 221) of the second test light generator 22
will be in the return period while the reflective face 120 (MEMS 121) of the first
test light generator 12 is in the middle portion of the scanning period.
[0145] As shown in FIG. 11, the scanning light source controller 41 then controls the first
optical system 10 and the second optical system 20 so as to switch the scanning of
the sensing area Sa with test light from the first light exit position 101 and the
scanning of the sensing area Sa with test light from the second light exit position
102 one line at a time.
[0146] As shown in FIG. 11, the scanning light source controller 41 controls the first optical
system 10 and the second optical system 20 so that the reflective face 220 (MEMS 221)
of the second test light generator 22 will be in the return period while the reflective
face 120 (MEMS 121) of the first test light generator 12 is in the approximate middle
of the scanning period. At this point, the reflective face 120 (MEMS 121) scans back
and forth with the test light while scanning the middle region in the second direction
of the sensing area Sa. The resolution of the scan can be enhanced by scanning back
and forth with the test light in the first direction.
[0147] As shown in FIG. 11, the scanning light source controller 41 controls the first optical
system 10 and the second optical system 20 so that the reflective face 120 (MEMS 121)
of the first test light generator 12 will be in the return period while the reflective
face 220 (MEMS 221) of the second test light generator 22 is in the approximate middle
of the scanning period. At this point, the reflective face 220 (MEMS 221) scans back
and forth with the test light while scanning the middle region in the second direction
of the sensing area Sa. The resolution of the scan can be enhanced by scanning back
and forth with the test light in the first direction.
[0148] When the scanning light source controller 41 controls the first optical system 10
and the second optical system 20 as shown in FIG. 11, the test light is scanned back
and forth over the middle region in the second direction of the sensing area Sa, so
the resolution of sensing is improved in the middle region in the second direction
of the sensing area Sa, and this affords more accurate sensing.
[0149] With the position sensing device A in this embodiment, the reflective face 120 (MEMS
121) of the first test light generator 12 is offset from the reflective face 220 (MEMS
221) of the second test light generator 22, but the frequency is the same. However,
the frequency need not be the same.
[0150] In the illustrated embodiment, with the position sensing device A or the positioning
sensing method as mentioned above, the return periods of the test lights (e.g., lights
or scanning lights) from the first and second light exit positions 101 and 102 (e.g.,
light exit positions) are offset with respect to each other, as illustrated in FIG.
11. The emissions of the test lights from the first and second light exit positions
101 and 102 (or the first and second light source component 11 and 21) are alternated
every time one line is scanned, as illustrated in FIG. 11. While the test light from
one of the first and second light exit positions 101 and 102 (e.g., the second light
exit position 102 as illustrated in the enlarged timing chart in FIG. 11) is in the
return period, the sensing area Sa (e.g., predetermined area) is reciprocally scanned
with the test light from the other one of the first and second light exit positions
101 and 102 (e.g., the first light exit positon 101 as illustrated in the enlarged
timing chart in FIG. 11).
FOURTH EMBODIMENT
[0151] Another example of the position sensing device in accordance with a fourth embodiment
will now be described through reference to the drawings. FIG. 12 is a simplified configuration
diagram of an example of the position sensing device in accordance with the fourth
embodiment. The light source position sensing device A1 shown in FIG. 12 includes
a scanning light source component 100a and the light receiver 300. The light source
position sensing device A1 is configured the same as the position sensing device A,
except that the relative positions of the first light exit position 101 and the second
light exit position 102 are different. Those components that are substantially the
same will be numbered the same and not described in detail again. Although not depicted
in the drawing, a processor that is the same as the processor 400 is provided.
[0152] As discussed above, the scanning frequency with test light in the first direction
is higher than the scanning frequency in the second direction. Therefore, in two-dimensional
scanning, the first direction (H direction) is the main scanning direction, and the
second direction (V direction) is the sub-scanning direction). The position sensing
device A has a configuration in which the first light exit position 101 and the second
light exit position 102 are separated from each other in the first direction (H direction)
of the scanning direction of the test light. Therefore, with the position sensing
device A, the first light exit position 101 and the second light exit position 102
are aligned in the main scanning direction.
[0153] With the position sensing device A1, however, the first light exit position 101 and
the second light exit position 102 are aligned in the sub-scanning direction, which
is the second direction (V direction). This layout affords greater latitude in how
the first light exit position 101 and the second light exit position 102 are disposed
in the position sensing device A1.
[0154] With the position sensing device A1, for the sake of contrast, the main scanning
direction and the sub-scanning direction are the same as in the position sensing device
A, that is, the main scanning direction is the first direction (horizontal direction),
and the sub-scanning direction is the second direction (vertical direction), but this
is not the only option. If the first direction (horizontal direction) is the sub-scanning
direction and the second direction (vertical direction) is the main scanning direction,
then it is possible for the first light exit position 101 and the second light exit
position 102 to have the same configuration as in the position sensing device A, in
which they are arranged in the first direction (horizontal direction).
FIFTH EMBODIMENT
[0155] Another example of the position sensing device in accordance with a fifth embodiment
will now be described through reference to the drawings. FIG. 13 is a simplified configuration
diagram of an example of the position sensing device in accordance with the fifth
embodiment. FIG. 14A is a diagram of two-dimensional scanning of test light from the
first light exit position. FIG. 14B is a diagram of two-dimensional scanning of test
light from the second light exit position. The position sensing device A2 shown in
FIG. 13 includes a scanning light source component 100b and the light receiver 300.
The light source position sensing device A2 is configured the same as the light source
position sensing device A, except that the relative positions of the first light exit
position 101 and the second light exit position 102 are different. Those components
that are substantially the same will be numbered the same and not described in detail
again. Although not depicted in the drawing, a processor that is the same as the processor
400 is provided.
[0156] With the position sensing device A and the position sensing device A1, the light
exit positions are aligned in the scanning direction (main scanning direction and
sub-scanning direction) in which the sensing area Sa is two-dimensionally scanned
with test light. With the position sensing device A2 shown in FIG. 13, the first light
exit position 101 and the second light exit position 102 are offset in both the first
and second directions, as viewed from the sensing area Sa.
[0157] FIG. 14A shows a state in which the sensing area Sa is two-dimensionally scanned
with test light from the first light exit position 101. The first direction (horizontal
direction) is the main scanning direction with a higher frequency, and the second
direction (vertical direction) is the sub-scanning direction with a lower frequency.
[0158] FIG. 14B shows a state in which the sensing area Sa is two-dimensionally scanned
with test light from the second light exit position 102. The first direction (horizontal
direction) is the sub-scanning direction with a lower frequency, and the second direction
(vertical direction) is the main scanning direction with a higher frequency.
[0159] Thus, the configuration can be such that the scanning direction of test light from
the first light exit position 101 is different from the scanning direction of test
light from the second light exit position 102.
[0160] With a configuration in which the main scanning direction and the sub-scanning direction
are not perpendicular, the area scanned with test light from the first light exit
position 101 and the area scanned with test light from the second light exit position
102 overlap in the sensing area Sa.
SIXTH EMBODIMENT
[0161] Another example of the position sensing device in accordance with a sixth embodiment
will now be described through reference to the drawings. FIG. 15 is a simplified layout
diagram of another example of the position sensing device in accordance with the sixth
embodiment. FIG. 16 is a timing chart of the operation of the position sensing device
shown in FIG. 15. Those components that are substantially the same as the components
described above will be numbered the same and not described in detail again.
[0162] As shown in FIG. 15, a position sensing device B includes a scanning light source
component 500 and the light receiver 300. Although not depicted in the drawing, a
processor that is the same as the processor 400 is provided. The scanning light source
component 500 includes a first light source component 11 and a second light source
component 21 configured the same as in the optical position sensor A, and a test light
generator 51 that includes a reflective face 510. The first light exit position 101
and the second light exit position 102 of the scanning light source component 500
are provided with a first reflector 61 and a second reflector 62 that reflect test
light generated by the test light generator 51 toward the sensing area Sa. The top
row of the timing chart in FIG. 16 shows the pivot angle in the second direction of
the reflective faces of the test light generator, and under this is shown the timing
of light emission by the first light source component and second light source component.
[0163] As shown in FIG. 15, the position sensing device B emits light from the first light
source component 11 and the second light source component 21 toward the test light
generator 51. As shown in FIG. 16, the first light source component 11 emits its light
when the reflective face 510 of the test light generator 51 has swung upward from
a middle position in the second direction. The light emitted from the first light
source component 11 is incident on and reflected by the first reflector 61 as test
light that has been scanned in the first and second directions. The test light reflected
by the first reflector 61 illuminates the sensing area Sa and scans over the sensing
area Sa.
[0164] Similarly, as shown in FIG. 16, the second light source component 21 emits its light
when the reflective face 510 of the test light generator 51 has swung downward from
a middle position in the second direction. The light emitted from the second light
source component 21 is incident on and reflected by the second reflector 62 as test
light that has been scanned in the first and second directions. The test light reflected
by the second reflector 62 illuminates the sensing area Sa and scans over the sensing
area Sa.
[0165] That is, with the position sensing device B, the first reflector 61 is provided to
the first light exit position 101, and light reflected by the first reflector 61 is
emitted as test light from the first light exit position 101. Also, the second reflector
62 is provided to the second light exit position 102, and light reflected by the second
reflector 62 is emitted as test light from the second light exit position 102.
[0166] As discussed above, with the position sensing device B, the scanning light source
controller 41 controls the scanning light source component 500 as above, and test
light can be emitted from two light exit positions with the single test light generator
51. Consequently, since fewer test light generators 51 are required, the structure
of the position sensing device B can be simplified.
[0167] The configuration is such that light from the first light source component 11 is
incident on the first reflector 61, and light from the second light source component
21 is incident on the second reflector 62, depending on the pivot angle of the reflective
face 510 of the test light generator 51 in the second direction. Accordingly, the
first light exit position 101 at which the first reflector 61 is disposed and the
second light exit position 102 at which the second reflector 62 is disposed are separated
in at least the second direction. Depending on the angles of the first light source
component 11 and the second light source component 21, it is also possible for the
first light exit position 101 and the second light exit position 102 to be offset
in both the first direction and the second direction.
[0168] In this embodiment, the configuration is such that test light is emitted from two
light exit positions by splitting the pivot angle of the reflective face 510 of the
test light generator 51 in the second direction in two, but this is not the only option,
and the configuration may instead be such that test light is emitted from three or
more light exit positions by splitting the pivot angle into three or more.
[0169] In this embodiment, the first reflector 61 is disposed at the first light exit position
101 and the second reflector 62 is disposed at the second light exit position 102,
with a reflector disposed at each of the plurality of light exit positions, but this
is not the only option. There may be light exit positions at which a reflector is
disposed and at which no reflector is disposed, and there may be light exit positions
at which test light reflected by a reflector is emitted, and light exit positions
at which test light is emitted directly from the optical system.
[0170] Also, a reflector may be provided at each light exit position, the reflectors made
movable (such as being able to slide or having a variable angle), and the test light
from the optical system emitted directly from certain light exit positions. Or, the
reflectors can be moved to adjust the test light illumination angle and change the
sensing area.
[0171] In the illustrated embodiment, with the position sensing device B as mentioned above,
the scanning light source component 500 includes the first and second reflectors 61
and 62 (e.g., reflectors) disposed at the first and second light exit positons 101
and 102 (e.g., at least one of the light exit positions), respectively. The first
and second reflectors 61 and 62 are configured to reflect the test light (e.g., light)
from the test light generator 51 (e.g., scanning light generator) toward the sensing
area Sa (e.g., predetermined area).
[0172] In the illustrated embodiment, with the position sensing device B as mentioned above,
the scanning light source component 500 includes the same number (two) of the first
and second light source components 11 and 21 (e.g., light sources) as the first and
second light exit positions 101 and 102 (light exit positions). The number (two) of
the first and second light source components 11 and 21 is larger than the number (one)
of the test light generator 51 (e.g., at least one scanning light generator). As illustrated
in FIG. 15, the test lights (lights) from the first and second light source components
11 and 21 are incident at different angles on the reflective face 510 of the test
light generator 51, and are led toward the corresponding light exit positions 101
and 102 (the corresponding reflectors 61 and 62), respectively.
[0173] In the illustrated embodiment, as illustrated in FIG. 15, the test light can be emitted
from two light exit positions with the single test light generator 51. However, the
position sensing device B can further include another test light generator, and the
configuration can be such that the lights from the first light source component 11
and the second light source component 21 are incident on the test light generators,
respectively, and that the lights reflected on the test light generators are further
incident on and reflected by the first and second reflectors 61 and 62, respectively,
to scan the sensing area Sa. With this configuration of the position sensing device
B, the scanning light source component 500 includes the same number (two) of the first
and second light source components 11 and 21 (e.g., light sources) as the first and
second light exit positions 101 and 102, and the same number (two) of the test light
generators (scanning light generators) as the first and second light exit positions
101 and 102.
SEVENTH EMBODIMENT
[0174] Another example of the position sensing device in accordance with a seventh embodiment
will now be described through reference to the drawings. FIG. 17 is a simplified layout
diagram of yet another example of the position sensing device in accordance with the
seventh embodiment. FIG. 18 is a timing chart of the operation of the position sensing
device shown in FIG. 17. As shown in FIG. 17, a position sensing device C includes
a scanning light source component 600 and the light receiver 300. Although not depicted
in the drawing, a processor that is the same as the processor 400 is provided. The
first reflector 61 is provided to the first light exit position 101 of the scanning
light source component 600, and the second reflector 62 to the second light exit position
102. The scanning light source component 600 includes a light source component 601,
a polarizer 602 (polarization switching component) included in the light source component
601, a test light generator 603, and a polarized beam splitter 604 (optical path switching
component). The light source component 601 has the same configuration as the first
light source component 11 of the position sensing device A, except that it includes
the polarizer 602, so the same components are numbered the same and will not be described
again in detail. Also, the test light generator 603 has the same configuration as
the first test light generator 12, and therefore will not be described again in detail.
[0175] The light source component 601 emits infrared light that has been linearly polarized.
The infrared light emitted from the light source component 601 is p-polarized light.
The laser light emitted from the light source component 601 is incident on the polarizer
602. The polarizer 602 is an element that converts the polarization direction of transmitted
light. The polarizer 602 used here is a combination of a polarization filter 6021
and a liquid crystal element 6022, but may instead be something else, and a wide range
of components capable of varying the polarization direction can be used.
[0176] The infrared light transmitted by the polarizer 602 is incident on the test light
generator 603. The test light generator 603 includes a reflective face 630 that pivots
in the first and second directions, and generates test light in which the infrared
light incident on the reflective face 630 is scanned in the first and second directions.
The test light generated by the test light generator 603 is incident on the polarized
beam splitter 604. The polarized beam splitter 604 has a reflective face that transmits
p-polarized light and reflects s-polarized light. If the test light incident on the
polarized beam splitter 604 is p-polarized light, it passes through the polarized
beam splitter 604 and is incident on the first reflector 61, and the test light reflected
by the first reflector 61 is scanned over the sensing area Sa. If the test light incident
on the polarized beam splitter 604 is s-polarized light, it is reflected by the reflective
face of the polarized beam splitter 604 and is incident on the second reflector 62,
and the test light reflected by the second reflector 62 is scanned over the sensing
area Sa.
[0177] With the position sensing device C, the processor 400 controls the polarizer 602
so that the polarization of the transmitted light is switched between p-polarization
and s-polarization. The light transmitted by the polarizer 602 is then switched to
p-polarization at the point of switching from the return period to the scanning period
in the second direction of the reflective face 630, the result being that the sensing
area Sa is scanned with test light from the first light exit position 101 to which
the first reflector 61 is provided. Similarly, light transmitted by the polarizer
602 is switched to s-polarization at the point of switching from the return period
to the scanning period in the second direction of the reflective face 630, the result
being that the sensing area Sa is scanned with test light from the second light exit
position 102 to which the second reflector 62 is provided.
[0178] The position sensing device C is configured to include one light source component
601 and one test light generator 603, which simplifies the configuration and allows
the position sensing device C to be made more compact.
[0179] In the illustrated embodiment, with the position sensing device C, the scanning light
source component 600 further includes the polarized beam splitter 604 (e.g., optical
path switching component) that is configured to alternately guide the optical path
of the test light (e.g., light) from the test light generator 603 to the first and
second light exit positions 101 and 102, as illustrated in FIG. 17.
[0180] In the illustrated embodiment, with the position sensing device C, the scanning light
source component 600 further includes the polarizer 602 (e.g., polarization switching
component) that is disposed between the light emitting element 111 (e.g., light source)
and the test light generator 603 (e.g., scanning light generator) and is configured
to switch the polarization direction of the light from the light emitting element
111. The optical path switching component includes the polarized beam splitter 604
that is disposed between the test light generator 603 and the first and second light
exit positions 101 and 102 and is configured to selectively guide the optical path
of the test light (e.g., light) from the test light generator 603 to the first and
second light exit positions 101 and 102 by reflecting or transmitting the test light
according to the polarization direction of the test light.
EIGHTH EMBODIMENT
[0181] Another example of the position sensing device in accordance with an eighth embodiment
will now be described through reference to the drawings. FIG. 19 is a simplified layout
diagram of yet another example of the position sensing device in accordance with the
eighth embodiment. FIG. 20 is a timing chart of the operation of the position sensing
device shown in FIG. 19.
[0182] The position sensing device D shown in FIG. 19 has the same configuration as the
position sensing device B, except that a scanning light source component 700 is provided.
Therefore, the components of the position sensing device D that are substantially
the same as in the position sensing device B are numbered the same and will not be
described again in detail.
[0183] As shown in FIG. 19, the position sensing device D includes the scanning light source
component 700 and the light receiver 300. Although not depicted in the drawing, a
processor that is the same as the processor 400 is provided. The first reflector 61
is provided to the first light exit position 101 of the scanning light source component
700, and the second reflector 62 to the second light exit position 102. The scanning
light source component 700 includes a light source component 71, a test light generator
72, and an optical path changing mirror 73 (optical path switching component). The
light source component 71 and the test light generator 72 are configured the same
as the first light source component 11 and the first test light generator 12 in the
position sensing device A, and will not be described again in detail.
[0184] As shown in FIG. 19, the optical path changing mirror 73 has a first mirror 731 and
a second mirror 732. The first mirror 731 and the second mirror 732 are aligned in
the first direction. The test light generated by the test light generator 72 is made
to be incident on the first mirror 731 or the second mirror 732 by being scanned in
the first direction.
[0185] When the reflective face 720 of the test light generator 72 pivots and the test light
is incident on the first mirror 731, it is reflected by the first mirror 731 (its
optical path is changed) and it is incident on the first reflector 61. The test light
is reflected by the first reflector 61, emitted from the first light exit position
101, and two-dimensionally scanned over the sensing area Sa.
[0186] Also, when the reflective face 720 of the test light generator 72 pivots and the
test light is incident on the second mirror 732, it is reflected by the second mirror
732 (its optical path is changed) and it is incident on the second reflector 62. The
test light is reflected by the second reflector 62, emitted from the second light
exit position 102, and two-dimensionally scanned over the sensing area Sa.
[0187] The operation of the position sensing device in this embodiment will now be described
through reference to the drawings. FIG. 21 is a diagram of how the reflective face
of the test light generator pivots, and how test light illuminates an optical path
changing mirror. FIG. 22 is a plan view of the optical path of the position sensing
device. FIG. 23 is a simplified diagram of a state in which a test area is scanned
with test light.
[0188] FIG. 21 is similar to FIG. 5A in that it shows at the top the change over time in
the pivot angle in the first direction, and on the left the change over time in the
pivot angle in the second direction. The rectangle indicates the optical path changing
mirror 73 as seen from the test light generator 72 side, with the left side of the
middle border being the first mirror 731, and the right side the second mirror 732.
[0189] As shown in FIG. 22, the test light generator 72 scans light from the pivoting light
source component 71 in the first and second directions, so that the light is incident
on the optical path changing mirror 73. The optical path changing mirror 73 is split
in the middle in the first direction into the first mirror 731 and the second mirror
732, and in FIG. 22, when the reflective face 720 pivots counterclockwise, the test
light scans the first mirror 731.
[0190] As shown in FIG. 21, when the optical path changing mirror 73 pivots the test light
from the left to the center, the test light is reflected toward the first reflector
61 from the left end k0 to the middle portion k1. Since the reflection inverts left
and right, the sensing area Sa is scanned from right to left with the test light from
the first light exit position 101.
[0191] When the reflective face 720 then pivots from the center to the right end, the test
light is reflected toward the second reflector 62 from the middle portion k2 to the
right end k3. Since the reflection inverts left and right, the sensing area Sa is
scanned from left to right with the test light from the second light exit position
102. Specifically, because the first mirror 731 and the second mirror 732 of the optical
path changing mirror 73 are disposed in the first direction, which is the main scanning
direction, the scanning of the sensing area Sa is performed back and forth, one line
at a time, with the test light from the first light exit position 101 and the test
light from the second light exit position 102.
[0192] As shown in FIG. 23, the scanning controller 412 pivots the reflective face of the
test light generator 72 so that the test light will go beyond the illumination range
in the first and second directions of the optical path changing mirror 73. The light
source controller 411 then controls the light source component 71 so that emission
of light stops when the test light leaves the range of the optical path changing mirror
73.
[0193] The scanning light source controller 41 need only control the light source component
71 and the test light generator 72 so that test light will fall within the optical
path changing mirror 73, so control is simple. Also, since one light source component
71 and one test light generator 72 are provided, the configuration can be simplified
and the device can be made more compact.
[0194] In this embodiment, an example is described in which the optical path changing mirror
73 includes two mirrors, namely, the first mirror 731 and the second mirror 732, but
this is not the only option. A optical path changing mirror in which three or more
mirrors are aligned in the scanning direction may be used, which will allow test light
to be emitted from three or more light exit positions.
[0195] Also, in this embodiment the optical path changing mirror 73 is configured such that
the two mirrors (the first mirror 731 and the second mirror 732) are aligned in the
first direction (the main scanning direction), but this is not the only option, and
they may instead be aligned in the second direction (the sub-scanning direction).
If a plurality of mirrors is aligned in the sub-scanning direction, the mirrors will
be switched whenever scanning of the sensing area Sa with test light reflected by
one mirror has been completed twice. For example, after the entire sensing area Sa
has been scanned twice with the test light from the first light exit position 101,
the entire sensing area Sa is scanned twice with the test light from the second light
exit position 102. The scanning is repeated in this way.
[0196] The coordinates of the user's finger Fg with respect to the first light exit position
101 and the coordinates with respect to the second light exit position 102 are determined
by the same method as in the first embodiment. Since the configuration is such that
the optical path is changed in the middle of the optical path changing mirror 73,
the relation between coordinates and the time since the start of emission from the
light source component 71 is different from that in the first embodiment.
[0197] In the illustrated embodiment, with the position sensing device D as mentioned above,
the scanning light source component 700 further includes the optical path changing
mirror 73 (e.g., optical path switching component) that is configured to alternately
guide the optical path of the test light (e.g., light) from the test light generator
72 to the first and second light exit positions 101 and 102, as illustrated in FIGS.
19 and 22.
[0198] In the illustrated embodiment, with the position sensing device D as mentioned above,
the optical path switching component includes the optical path changing mirror 73
(e.g., reflection member) that has the first and second mirrors 731 and 732 (e.g.,
reflective faces) that are configured to selectively reflect the test light (e.g.,
light) to the first and second reflectors 61 and 62 (e.g., a plurality of reflectors)
according to the incidence position of the test light on the first and second mirrors
731 and 732 in the first direction.
[0199] In the illustrated embodiment, with the position sensing device D as mentioned above,
the first and second mirrors 731 and 732 are split in the first direction.
NINTH EMBODIMENT
[0200] Another example of the position sensing device in accordance with a ninth embodiment
will now be described through reference to the drawings. FIG. 24 is a timing chart
of the operation in yet another example of the position sensing device in accordance
with the ninth embodiment. The configuration of the position sensing device D in this
embodiment is the same as that in the eighth embodiment, so the configuration will
not be described again.
[0201] With the position sensing device D, there is a period during which the spot of test
light generated by the test light generator 72 that illuminates the optical path changing
mirror 73 illuminates both the first mirror 731 and the second mirror 732 in the middle
border portion. Therefore, as shown in FIG. 24, the light source controller 411 stops
the emission of infrared light from the light source component 71 when the test light
spot goes beyond the boundary of the first mirror 731 and the second mirror 732. This
suppresses the emission of test light simultaneously from the first light exit position
101 and the second light exit position 102, and improves sensing accuracy.
[0202] In the illustrated embodiment, with the position sensing device D as mentioned above,
the processor 400 is configured to control the light source component 71 (e.g., light
source) to stop emitting the test light (e.g., light) while switching the first and
second light exit positions 101 and 102, as illustrated in FIG. 24.
TENTH EMBODIMENT
[0203] Another example of the position sensing device in accordance with a tenth embodiment
will now be described through reference to the drawings. FIG. 25 is a plan view of
the optical path changing mirror used in the position sensing device in accordance
with the tenth embodiment. The configuration of the position sensing device D in this
embodiment is the same as that in the eighth embodiment, except that the optical path
changing mirror 73 has a different shape, so the configuration will not be described
again.
[0204] With the position sensing device D in this embodiment, an MEMS is used to pivot the
reflective face 720 of the test light generator 72. As discussed above, an MEMS pivots
by means of the force of an actuator and the elastic force of an elastic support.
In pivoting under elastic force, the force generated varies with the twisting angle,
and this affects the rate of pivoting. Consequently, the rate at which the test light
spot moves ends up being uneven, and an object in the sensing area Sa is not sensed
as accurately. In view of this, as shown in FIG. 25, the first mirror 731 and the
second mirror 732 are given a convex shape, so that the optical paths of reflected
light at regular time intervals are aligned equidistantly.
[0205] With this configuration, movement in the main scanning direction of the test light
emitted from the first light exit position 101 and the second light exit position
102 will be at a constant or substantially constant speed, and a sensing object can
be sensed more accurately. Although the first mirror 731 and second mirror 732 are
given a convex shape here, this is not the only option.
[0206] In the illustrated embodiment, with the position sensing device D as mentioned above,
the first and second mirrors 731 and 732 (e.g., reflective faces) have a shape such
that scanning rate of the test lights (e.g., scanning lights) in the sensing area
Sa (e.g., predetermined area) is a constant.
ELEVENTH EMBODIMENT
[0207] Another example of the position sensing device in accordance with an eleventh embodiment
will now be described through reference to the drawings. FIG. 26 is a simplified layout
diagram of yet another example of the position sensing device in accordance with the
eleventh embodiment. FIG. 27 is a block diagram of how the position sensing device
shown in FIG. 26 is connected. FIG. 28 is a graph of the transmission wavelength of
a filter provided to the light receiver of the position sensing device shown in FIG.
26. The position sensing device A3 shown in FIG. 26 has the same configuration as
the position sensing device A, except that it includes a scanning light source component
100e and a light receiver 300a. Therefore, those components of the position sensing
device A3 that are substantially the same as in the position sensing device A will
be numbered the same and will not be described again in detail.
[0208] The scanning light source component 100e includes a first optical system 10e and
a second optical system 20e. The first optical system 10e includes a first light source
component 11 e that includes a laser light emitting element 111 e that emits infrared
light with a wavelength R1, and a first test light generator 12. The first light source
component 11 e is optimized to infrared light with the wavelength R1, but the basic
configuration is the same as that of the first light source component 11, so components
that are the same will be numbered the same and will not be described again in detail.
[0209] Meanwhile, the second optical system 20e includes a second light source component
21 e that includes a laser light emitting element 211 e that emits infrared light
with a wavelength R2, and a second test light generator 22. The second light source
component 21 e is optimized to infrared light with the wavelength R2, but the basic
configuration is the same as that of the second light source component 21, so components
that are the same will be numbered the same and will not be described again in detail.
[0210] More specifically, with the position sensing device A3, the scanning light source
component 100e emits test light of the wavelength R1 from the first light exit position
101, and emits infrared light of the wavelength R2 from the second light exit position
102.
[0211] The light receiver 300a has a first light receiving element 31 a and a second light
receiving element 31 b disposed in alignment. A lens 33a is provided adjacent to the
light receiving face of the first light receiving element 31 a, and a lens 33b adjacent
to the second light receiving element 31 b. Furthermore, a first filter 32a that transmits
infrared light of the wavelength R1 and blocks infrared light of the wavelength R2
is provided near the opposite side of the first lens 33a from the first light receiving
element 31 a. Also, a second filter 32b that blocks infrared light of the wavelength
R1 and transmits infrared light of the wavelength R2 is provided near the opposite
side of the second lens 33b from the second light receiving element 31 b.
[0212] The vertical axis in FIG. 28 transmittance, and the horizontal axis is wavelength.
If we assume that the wavelength R1 < the wavelength R2, then the first filter 32a,
as shown in FIG. 28, can be a low-pass filter that cuts out wavelengths of R3 or higher
(R1 < R3 < R2). The second filter 32b can be a highpass filter that cuts out wavelengths
of R3 or lower. This is not the only option, however, and a band pass filter that
transmits the various light reception wavelengths may be provided.
[0213] As shown in FIG. 27, the first light receiving element 31 a and the second light
receiving element 31 b each individually send light reception signals to the receiver
421. The receiver 421 associates the light reception signal from the first light receiving
element 31 a and the light reception signal from the second light receiving element
31 b with a synchronization signal, and sends the result to the arithmetic unit 422.
[0214] The first light source component 11 e and the second light source component 21 e
emit light of different wavelengths, and since light of each wavelength is selectively
received by the first light receiving element 31 a and the second light receiving
element 31 b, it is easy to determine whether the light was emitted from the first
light exit position 101 or the second light exit position 102.
[0215] Also, since the light beams have different wavelengths, even if the light beams emitted
from the first light source component 11e and the second light source component 21
e simultaneously illuminate the sensing area Sa, it will still be possible to determine
from which light source (light exit position) the light was emitted. Therefore, with
the position sensing device A3, the timing of emission need not be synchronized for
the test light from the first light exit position 101 and the test light from the
second light exit position 102. For example, test light from the first light exit
position 101 and test light from the second light exit position 102 may illuminate
the sensing area Sa at the same time.
[0216] In this embodiment, test light of different wavelengths is emitted in order to identify
the test light, but this is not the only option. For instance, the configuration may
include a scanning light source component that causes light of different polarization
directions to be incident in the sensing area, and a polarization filter that transmits
or blocks according to the polarization direction in addition to a band pass filter
or instead of a band pass filter.
[0217] In the illustrated embodiment, with the position sensing device A3 as mentioned above,
the light receiver 300a (e.g., at least one light receiver) has the same number (two)
of first and second light receiving elements 31 a and 31 b with first and second filters
32a and 32b (e.g., light receivers) as the first and second light exit positions 101
and 102 (e.g., light exit positions). The test lights (e.g., lights or scanning lights)
from the first and second light exit positons 101 and 102 have different wavelengths
R1 and R2 with respect to each other. The first and second light receiving elements
31 a and 31 b with the first and second filters 32a and 32b have band properties to
receive the test lights (e.g., lights or scanning lights) from the corresponding light
exit positions 101 and 102, respectively.
TWELFTH EMBODIMENT
[0218] FIG. 29 is a simplified configuration diagram of the position sensing device in accordance
with a twelfth embodiment. FIG. 30 is a block diagram of the electrical connections
of the position sensing device shown in FIG. 29. The position sensing device A4 shown
in FIGS. 29 and 30 includes a scanning light source component 100f, a light receiver
300, and a light receiver 310. Although not depicted in the drawing, a processor that
is the same as the processor 400 is provided. The light source position sensing device
A4 has substantially the same configuration as the position sensing device A, except
that it includes three light exit positions and two light receivers 300 and 310, so
components that are substantially the same are numbered the same and will not be described
again in detail.
[0219] The scanning light source component 100f of the position sensing device A4 shown
in FIGS. 29 and 30 includes the first light exit position 101, the second light exit
position 102, and a third light exit position 103. The first light exit position 101,
second light exit position 102, and third light exit position 103 are respectively
provided with the first optical system 10, the second optical system 20, and a third
optical system 30. The first optical system 10, second optical system 20, and third
optical system 30 have substantially the same configuration, and will therefore not
be described in detail.
[0220] With the position sensing device A, the sensing area Sa is two-dimensionally scanned
with test light from the first light exit position 101 and the second light exit position
102, and the three-dimensional coordinates of a sensing object are computed by using
the first light exit position 101 and the second light exit position 102 as a reference.
With just two light exit positions, distortion or movement of a sensing object may
make it impossible to acquire the three-dimensional coordinates of the sensing object.
Therefore, the third light exit position 103 is disposed so as to emit test light
at a position that would be difficult to illuminate with just the test light from
the first light exit position 101 and the second light exit position 102. Furthermore,
the light receiver 310 is provided in addition to the light receiver 300. The light
receiver 310 has the same configuration as the light receiver 300, and is disposed
at a position where it can receive reflected and/or scattered light that could not
be received by the light receiver 300.
[0221] The light receiver 300 and the light receiver 310 are both connected to the receiver
421, and light reception signals from the light receiver 300 and the light receiver
310 are received by the receiver 421. The scanning light source component 41 controls
the first optical system 10, second optical system 20, and third optical system 30
so that the scanning of the sensing area Sa with the test light emitted from the first
light exit position 101, second light exit position 102, and third light exit position
103 is performed in time series. Therefore, the arithmetic unit 422 can confirm from
the synchronization signal and the light reception signal whether the test light was
emitted from the first optical system 10, the second optical system 20, or the third
optical system 30.
[0222] Also, providing three light exit positions also makes it possible to acquire the
shape of a sensing object within the sensing area Sa.
[0223] With the position sensing device A4 in this embodiment, three light exit positions
and two light receivers are provided, but this is not the only option, and there may
be more than three light exit positions. Also, there may be just one light receiver,
or two or more of them.
[0224] Embodiments of the present invention were described above, but the present invention
is not limited to or by the content of these embodiments. Also, various modifications
are possible without departing from the gist of the invention. Also, the above embodiments
examples can be combined as needed.
[0225] (1)To achieve the stated object, the present invention provides a position sensing
device having a scanning light source component that emits test light from a plurality
of different light exit positions and scans a sensing area with the test light emitted
from the various light exit positions, a light receiver that receives sensing light
reflected or scattered by a sensing object located in the sensing area and outputs
a light reception signal, and a processor that controls the scanning light source
component and calculates the position of the sensing object based on the light reception
signal, wherein the processor determines from which light exit position the light
reception signal is obtained by receiving the sensing light based on the test light
that is emitted, and senses the position of the sensing object by computation based
on the optical path of the test light thus determined.
[0226] With this configuration, the position of the sensing object can be calculated by
scanning the sensing area with the test light emitted form a plurality of light exit
positions, and detecting the light reflected or scattered by the sensing object located
within the sensing area, so there is more latitude in the position where the light
receiver is attached. Accordingly, there are fewer restrictions on the shape and installation
location of the position sensing device, and the device can be made more compact.
[0227] The above configuration may be such that the scanning light source component includes
a light source that emits light, and an test light generator that generates test light
by moving the optical path of the light in a first direction and in a second direction
that intersects the first direction, and the processor controls the drive of the light
source and the test light generator. With this configuration, it is easy to drive
the light source and the test light generator in synchronization. Consequently, the
position of the sensing object can be accurately sensed.
[0228] The above configuration may be such that a reflector that reflects test light generated
by the test light generator toward the sensing area is provided to at least one of
the light exit positions. With this configuration, since the optical path of the test
light can be changed by the reflector, there is greater latitude in the layout of
the members of the position sensing device. Examples of the members include a light
source and an test light generator, but are not limited to these.
[0229] The above configuration may be such that the light source and the test light generator
are provided in the same number as the light exit positions to the scanning light
source component. Providing the same numbers of light sources and test light generators
allows the test light to accurately illuminate the sensing area, and allows the sensing
area to be scanned with the test light without any gaps.
[0230] The above configuration may be such that the processor stops the emission of test
light from the other light exit position when test light is being emitted from one
light exit position, and the processor acquires information about the time when the
light receiver has received sensing light. With this configuration, since the emission
of test light is performed exclusively in time series, the light exit position where
the sensing light is emitted can be identified even though there are few light receivers.
Consequently, the configuration can be simplified, and a sensing object within the
sensing area can be accurately sensed.
[0231] The above configuration may be such that the processor starts the scanning of the
sensing area with the test light emitted from the next light exit position after the
scanning of the entire sensing area with the test light emitted from one light exit
position has ended. With this configuration, it is easier to synchronize the scanning,
and control can be simplified.
[0232] The above configuration may be such that two of the light exit positions are provided,
and the processor controls the scanning light source component so that the scanning
return period of the test light emitted from the various light exit positions is shifted,
and the light exit position from which the test light is emitted is switched every
time one line is scanned with the test light, thereby performing reciprocal scanning
with the test light from the other light exit position when one light exit position
is in its return period. With this configuration, there is no need for the two test
light generators to be operated in synchronization, and a sensing object can be sensed
simply and accurately. Also, since the control is so simple, the controller can be
simplified, which reduces manufacturing costs. Furthermore, test light generators
of different drive frequencies can be used. This allows test light generators with
lower drive frequency accuracy to be used.
[0233] The above configuration may be such that there are the same number of the light receivers
as the light exit positions, the scanning light source component is formed so as to
emit test light of different wavelengths from the various light exit positions, and
the light receivers receive light of the same wavelength as the light emitted from
the corresponding light exit positions. With this configuration, from which light
exit position the test light is emitted can be determined even when test light is
emitted from two or more places at the same time. Consequently, there is less deviation
in time when scanning with test light from multiple light exit positions, and the
sensing object can be sensed more accurately. Also, since a plurality of beams of
test light are emitted at the same time, there is no need to synchronize multiple
light sources and multiple test light generators, so the scanning light source controller
can be simplified. This allows manufacturing costs to be reduced without lowering
the accuracy with which a sensing object is sensed.
[0234] The above configuration may be such that the same number of light sources as the
light exit positions are provided to the scanning light source component, a smaller
number of the test light generators than the light sources are provided, and the light
sources are disposed so that their light will be incident at different angles on the
test light generators, and are disposed so that the test light will be incident at
the corresponding light exit positions.
[0235] The above configuration may be such that the scanning light source component comprises
one light source, one test light generator, and an optical path switching component
for alternatively switching the optical path of the test light to any of the light
exit positions. With this configuration, the number of light sources and test light
generators can be reduced, and manufacturing costs will be lower. Also, there will
be greater freedom in the layout of the light sources and test light generators, depending
on the layout of the member that converts the optical path of the test light.
[0236] The above configuration may be such that the optical path switching component comprises
a polarization switching component that is disposed between the light source and the
test light generator and switches the polarization direction of light, and a polarized
beam splitter that is provided along the optical path of the test light between the
test light generator and the light exit positions, and that switches the optical path
of the test light by reflecting or transmitting light depending on the polarization
direction.
[0237] The above configuration may be such that the optical path switching component comprises
a reflection member that includes a reflective face that selectively reflects the
test light to one of a plurality of reflectors depending on the incidence position
of the first direction of the test light.
[0238] The above configuration may be such that the reflective face has a split face that
is split in the first direction.
[0239] The above configuration may be such that the reflective face has a shape such that
the scanning rate with the test light in the sensing area will be a constant rate.
[0240] The above configuration may be such that the scanning light source controller can
controls the exit light of the light source so that the emission of light will stop
before or after switching of the light exit position at which the test light is incident.
[0241] The present invention provides a position sensing device with which members can be
laid out with greater freedom, and the position of a sensing object in a sensing area
can be sensed accurately.
[0242] The present invention also provides a spatial input device with which input from
the user's finger to a spatial image can be reliably detected with a simple configuration.
[0243] In understanding the scope of the present invention, the term "comprising" and its
derivatives, as used herein, are intended to be open ended terms that specify the
presence of the stated features, elements, components, groups, integers, and/or steps,
but do not exclude the presence of other unstated features, elements, components,
groups, integers and/or steps. The foregoing also applies to words having similar
meanings such as the terms, "including", "having" and their derivatives. Also, the
terms "part," "section," "portion," "member" or "element" when used in the singular
can have the dual meaning of a single part or a plurality of parts unless otherwise
stated.
[0244] While only selected embodiments have been chosen to illustrate the present invention,
it will be apparent to those skilled in the art from this disclosure that various
changes and modifications can be made herein without departing from the scope of the
invention as defined in the appended claims. For example, unless specifically stated
otherwise, the size, shape, location or orientation of the various components can
be changed as needed and/or desired so long as the changes do not substantially affect
their intended function. Unless specifically stated otherwise, components that are
shown directly connected or contacting each other can have intermediate structures
disposed between them so long as the changes do not substantially affect their intended
function. The functions of one element can be performed by two, and vice versa unless
specifically stated otherwise. The structures and functions of one embodiment can
be adopted in another embodiment. It is not necessary for all advantages to be present
in a particular embodiment at the same time. Every feature which is unique from the
prior art, alone or in combination with other features, also should be considered
a separate description of further inventions by the applicant, including the structural
and/or functional concepts embodied by such feature(s). Thus, the foregoing descriptions
of the embodiments according to the present invention are provided for illustration
only, and not for the purpose of limiting the invention as defined by the appended
claims.